Every Friday afternoon in Luanda, in Independence Square, Angolan television records its most popular show. Flunkies struggle up trees to hang banners while elegant young producers purr into their mobile phones. Camera positions are chalked out on the ground, TV monitors are set in place and this week's participants directed into two long lines - one for women and one for men.

"Well, you know how we men are," chortles this week's presenter, Jorge Madeira, when I ask why the men and women are separated. As we chat, Madeira tells me that he was part of the news crew that filmed the body of Jonas Savimbi, the leader of the rebel Unita movement who was killed by government forces in February 2002. "Did you realise immediately," I ask, "that his death meant the end of the war?" Madeira does not hesitate: "Yes." Fighting began in Angola in 1961.

You could easily be forgiven for thinking that we were about to watch the recording of a peculiar and popular gameshow. After all, the Pan-African Big Brother Africa was a huge hit across the continent, although Bruna, the Angolan housemate, was the first to be evicted. Once the cameras begin to roll, the men and women trot forward as they reach the front of their respective lines, many flash a photo to the camera, and then record a 30-second clip.

Meanwhile, Madeira and his team are keeping some of the participants in the background. They are this week's winners. Since everyone who has a TV watches the show, they have a fair idea of what is coming. Still, Madeira says of Joana Domingas, one of the group waiting: "Don't tell her! We are going to reunite her with her brother, but she doesn't know yet!"

Suddenly, it's all action. A cameraman is sprinting across the square with Joana's brother, Luis Bernardo, who had recorded a message the week before. He's thrust into the arms of Joana, who came from the coastal city of Benguela after someone told her they had seen him on television. The team have already recorded a sequence of her watching his clip, in which he says he is hunting for his family. "Are you sure it is him?" they ask her. "Yes, yes," she replies. "It is him."

Now it's all hugs, smiles and shock. Well, it would be if you had not seen your brother, a former soldier now minus a hand, since 1981. And, of course, the prosperous looking Joana might be feeling some trepidation seeing her shabbily dressed brother looking as if he might be planning to tap her for money. If any such thought is crossing her mind, no one wants to know about it, and besides, the crew have not finished with them yet. They need to complete their sequence. Brother and sister are shown what to do - basically, walk away into the sunset together.

This is Nacao Coragem - Courageous Nation. It is not a gameshow, of course, but one part of a giant effort being made across the country to reunite thousands - or more likely hundreds of thousands - of people separated by decades of war. The photographs that people flash before the cameras are treasured pictures of loved ones, some they have not seen for almost 30 years, some black-and-white images of children who, if they are still alive, will be middle-aged now.

Armed conflict broke out in Angola in 1961, when it was still a Portuguese colony. Since then, fighting has ravaged this oil-rich southern African country with little respite until last year. When the Portuguese left in 1975, the independence struggle, which in terms of death and destruction was as nothing compared with what was to come, mutated into a ghastly civil war fuelled at first by tribal loyalties but on to which were grafted the struggles of the superpowers that sponsored Cuba and apartheid South Africa to intervene. The Cubans fought on the side of the (then) Marxist MPLA party, which had established itself as the government after seizing the capital, Luanda; the South African army invaded in 1975 and backed Unita, led by Jonas Savimbi. He successfully wowed western conservatives - Reagan received him at the White House - convincing them that he was the future of African democracy and not a brutal, power-hungry maniac.

By 1992, as exhaustion set in and with the demise of the Soviet Union, the MPLA and Unita agreed to a ceasefire and elections. Savimbi lost and went back to the bush to war. In Luanda, 6,000 of his fellow Ovimbundu tribesmen were killed in reprisals.

From 1994 to 1998, a loose ceasefire held, but then the war began again in earnest. Unita took the government by surprise, but when international sanctions were placed on the rebels for refusing to end the war, its initial successes were reversed.

By the time Savimbi was killed early last year, his movement had been utterly enfeebled. By April, a ceasefire had been agreed, Savimbi's forces were demobilised and plum jobs were handed out to many former top Unita commanders and officials. It is a process that has worked surprisingly well, testament, perhaps, to shrewd manoeuvring from the government and the complete exhaustion of everybody. But far from being dead, Unita, at its recent congress in which a new leader was voted in, has now transformed into a political party and is looking forward to elections, probably in 2005.

So, with the exception of the northern enclave of Cabinda, which produces 60% of Angola's oil and where separatist rebels have been fighting for independence, the rest of the country is finally at peace. The conflict is believed to have left a million dead and, at least since 1975, to have displaced four million people, or one third of the population, within the country and to have left another half a million as refugees outside. Now Angolans are trying to rebuild their lives and their families. No one knows the exact figures, but it is believed that, since the death of Savimbi, more than a million people have been on the move, trekking home, looking for lost loved ones.

In many other conflicts, those in the Balkans, for example, families separated by frontlines could eventually find each other by telephone via a cousin in Germany, say. But in Angola there were, and are, simply no communications for families scattered across a country twice the size of France. Mines and poverty make travel all but impossible.

Throughout the week, Nacao Coragem broadcasts clips of up to 500 people looking for relatives. But the show is only part of the effort being made by both Angolans and foreigners to help reunite families. A lead role is being played by the International Committee of the Red Cross (ICRC), which has begun compiling and publishing ever growing lists of the missing. It has also initiated an active, detective-like service to reunite children and their families, including demobilised child soldiers, of whom there are thousands.

To listen to the stories of those searching and those who have been reunited is to understand a tiny fraction of the suffering produced by a conflict that dragged on for so long that whole generations grew up never knowing peace. When it ended, few even knew what it had been about. The MPLA, which began in government so idealistically in the mid-70s, focusing on health and education, took control of vast oil revenues, and its leaders are widely reputed, by diplomats and civil society activists based in Luanda, to now number among them some of the richest people on the planet; Unita, meanwhile, had a grip on much of Angola's diamond wealth.

Far from the purring producers and the excitement of the television cameras, much of the grinding work of putting families back together takes place deep in the interior of this shattered country. It takes place in many of the areas previously held by Savimbi that, even today, are only just becoming accessible to the Red Cross and others because of the time it has taken to clear roads of mines - that is, mines embedded in the soil of the horribly rutted tracks that pass for roads in most of the country. Nacao Coragem does not reach these parts. Even if people did have money to buy televisions, which they do not, there is no electricity.

In a large open space by the village of Kamuenho, some 300 miles south-east of Luanda, the Red Cross has gathered up to 10,000 people to hand out aid. Most of them have just returned home to this region, which saw much fierce fighting. Soon, they will get seeds from the UN's World Food Programme (WFP) and, if all goes well, will begin planting them. Already large areas of bush are blazing as they begin to clear the land. For now, though, they have virtually nothing, and as is so striking in this country, which earns between $3bn and $5bn a year from oil receipts, the government is conspicuous by its absence.

In Kamuenho, the Red Cross is handing out cooking oil, flour, hoes, vegetable seeds and blankets. Most of these people have never seen any aid - the region has been inaccessible to aid workers since 1987. Everyone waits, quietly and patiently; on the margins, young actors are performing a show. They are telling people that if they have lost family, they can report to Red Cross officials, who are on hand to take down details.

Rosa Nangombe, one of four tracing officials, sits in the shade of a lorry and writes as 38-year-old Sergio Ernesto tells his tale in a typically matter-of-fact way. He is looking for two of his four children: Anice, a girl who would be 10 now, and a son, Feliciano, who would be six. The family had lived in a Unita-controlled area and he had lost his children when the area was attacked by government troops. "Their mother is dead. It was in Mavinga. Our village was being bombed. It was in 2001. We were running away when we were attacked by government soldiers. I have found the one who was two years old and I still have my eldest, but I don't sleep. I have been waiting for something to happen. Until now, I did not know about this service."

Once his details are logged, Sergio ambles back to join the lines for his aid handout. He is followed by Rosalina Jamba, 63. "Someone had died," she says. "I went to the funeral and left the children at home. They went to the fields, looking for food. The eldest was 20, and her baby son, who was one, was on her back. The others were a boy aged 18, a girl of six and another boy of 12."

While she was away, Unita attacked her village. She hasn't seen her children since. The attack was in 1982. "I went for a long time without eating," says Rosalina. "I could not imagine making food in a small pot when I was used to making it in a big one. I still have to think about them, because I did not bury them, so I can't forget them." With such huge numbers of people now moving about the country, some families are being reunited without help. Rosalina says: "Many lost children, but some of them are now, slowly, coming back. I am still waiting."

The nature of the conflict was such that children scattered by the war or captured were not simply left to fend for themselves. Groups such as the New York-based Human Rights Watch have chronicled the fate of captured boys and girls - while many were used as cannon fodder, porters or sex slaves, especially but not only by Unita, many found themselves allotted to families and, if they were lucky, more or less adopted.

Branca Jose Reciado, now 18, was reunited with her family in February. She was captured in 1998, when she was 13. Her mother had died in 1992 and her father, who could not cope with four children, had sent her to a boarding school run by nuns near where they used to live in Malanje, a province west of Luanda.

"It was a surprise," says Branca. "Unita came at midnight. The nuns came around the dormitories telling us to come out, but I went back to find my younger sister, and that's when they found me. They chose five boys and 10 girls, and I was the youngest of the girls. We were taken to their base. Others 'got married' - they were forced into that. I had to cook and wash and dance for celebrations. I was not abused, but I had a guardian who looked after me. A general. I was attached to his family and looked after his children. He was called Big Joe.

"After the death of Savimbi, everyone was dispersed. The general died. He was killed. Some of his family and his wife died at the same time." His children escaped, and Branca says she misses them: "But I don't know where they are now." I ask what she thinks of Unita now that it has become a political party. "I hate Unita," she says, but adds, "Big Joe was a good man. He took care of many others." But in Luanda, where Branca now lives with her family, many remember him as "pitiless" and "brutal".

In a way, Branca's comment is typical of something extraordinary here - that is, the lack of rancour and personal bitterness, a phenomenon I found wherever I went in Angola. Even more extraordinary is the fact that former fighters in a civil war that pitted brother against brother now live next door to one another without any problem. It was something I heard time and again. People fought because they were mobilised and ordered to fight, not, in the vast majority of cases, because they wanted to or because they believed in a cause.

Of the 10 girls captured at the same time as Branca, only three survived. "Some died in the war, others of hunger and others of sickness," she says. The five boys all survived.

As we sit in the family's little yard, Branca's father, Jose Reciado Kalandula, and her 89-year-old grandmother, Feliciana Manuel, interject every now and then. I ask if the family had heard any news during the years of separation. "Nothing, nothing, nothing," says Feliciana. Still, they say, they had always hoped she might still be alive. The nuns had assured them they would pray for Branca.

But, finally, they gave up hope."Someone said, 'When they take them, they are dead,' " says Jose. So the family decided to let go. "We mourned for her. It was a symbolic thing, at home, it was a gathering. It was a moment of sadness. I was still hopeful, but at the same time I thought she was dead." A month later, Branca, who at the end of the war registered with the Red Cross, showed up.

Branca's story has ended happily. Clearly, she has come back to a loving family and is having little problem in adapting to her new life. But it is not always like this. The Red Cross has found cases where missing loved ones have refused to return home, having built themselves new lives. Several of those I talked to were clearly attached to the families they had lived with, some of whom were equally upset to lose them.

In another little yard close to Luanda's international airport, and with planes occasionally roaring overhead, Anita Bernardo, a 16-year-old who was captured at the age of 10 and also reunited in February, tells me what had happened to her.

"It was in the village of Kakaluma. I went to the fields with friends. Unita arrived and we tried to flee, but I was caught. I was put under the care of a lady called Tarbita Eriqeta. She was married to a lieutenant and had three children. My job was to look after the fields, and I helped look after the children. I was in charge of the kitchen. They treated me as a daughter. Working in the fields was very difficult. There was fighting, bombing from the air, and we ate food without salt. Many times we were hungry. It was in the bush, in a base with grass huts. They used to say, 'Your mother is dead, your parents are dead, forget about them.' Sometimes, I even dreamed they were dead."

With the end of the war, Anita ended up in a quartering area for demobilising Unita soldiers, which is where nuns found her and took her to the Red Cross.

Christina Muanya, Anita's mother, says, "My niece told me she was captured. I felt terrible. I lost my appetite and the courage to carry on. We thought she was dead, as Savimbi had the habit of killing. Later on, someone escaped from there and told us she was alive. I was very relieved. I prayed for her. Yes, she came back different, but in character she didn't change much."

I ask Anita about her father, and she says glumly, "My father is not interested in me. I've met him once since I've come back, and he did not say anything. I was very disappointed because I needed money to pay for tuition, but he has many wives and children."

In January, Anita will go back to school. She had no education in the years she lost, but she does know that she wants to be a doctor.

Bobbing on the edge of the scene is Anita's 15-year-old half-sister, Fininya Albino. I ask what it is like to have her sister back. "She has changed a lot. When she came, she came with backward habits acquired in the bush. She is very badly behaved and her accent is out of date. She is not civilised. She is peasant-like and stubborn, and likes her old ways."

Anita turns away, looking crushed. Talking in a virtual whisper, Anita will say only that, while she does have friends, "I like to go out and be by myself. People see me in a strange way, because of my accent and being different. Some are friendly, but some are not."

We are flying to Huambo in a small Red Cross plane. The plane has called in at the small town of Kuito to collect Filomena Belo. If she is excited at the prospect of seeing her lost daughters again, she is not showing it; perhaps she is nervous. Huambo, with its wide avenues and now mostly decrepit or shattered villas, was once Nova Lisboa, or New Lisbon. There is virtually no traffic in the streets because nobody has a car. But people who live here say that the difference from a year ago is incredible - there are now three times more cars on the roads.

We head for the outskirts of town, where Filomena is to be reunited with Cecilia, 15, and Lurdes, 14, who were captured by Unita in 2001 when they went to grind corn. They were living with Fadario Hama, their uncle, a man who had been a Unita soldier for 28 years, from the age of 16. Now, as Filomena greets them, there are joyous hugs and kisses. When I ask tentatively what happened immediately after they were captured, Cecilia bursts into tears, overwrought, reluctant to recount in front of her mother the horrors she experienced then. Filomena sits with a hand over her face.

"We were used as a labour force," Cecilia says finally. "We carried mines and food on our heads and on our backs. There were a lot of children. I lived in the home of Colonel Nato, who died. I prepared food. I was treated the same as other children, and there were others there who had been kidnapped."

I ask Fadario why Unita captured children. He says simply, "It was a war, and war is that." Fadario tells me that, when he heard that the girls had been captured by his own side, he had moved quickly to get them back. Recently, with the rest of his family, they had come back to Huambo, for which Unita and the government had fought bitterly. Still, like many people, Fadario does not want to dwell on the past. He wants to look forward, and today his problem is that he doesn't have a job. Still, he does have some good news for Filomena. He has been in touch with her father, Domingos Kavangio, who is 81 and lives in a small town called Katchiungo, about an hour and a half away by car. She has not seen him, or heard anything of him, since 1981.

Filomena and her father would not normally be offered transport from the Red Cross to be reunited - help for adults is usually limited to re-establishing communications - but since we are going in that direction the next day, she is invited to come along.

Once we get to Katchiungo, Domingos has to be found. He lives alone in a tiny room and leaves for his fields at 5.30 in the morning. A local Red Cross volunteer speeds off on his motorbike to hunt for him. When he arrives, Domingos, who has had just moments to take in what is about to happen, is so overcome that he hardly knows what to say to Filomena. He croaks, "Oh my daughter - I can't speak." The granddaughters, whom he has never seen, kiss him politely. "I never thought I would see her again," says Domingos. "The war was so tough."

In Katchiungo, women employed by the local council sweep the main street and clip its little hedges to keep them tidy. Many of its once pretty colonial-era buildings lie in ruins. At the station, where a sign preserving the old colonial name of Bela Vista remains, men from Unita and their families, now demobilised and on their way home, are camping on the platform, in wagons and warehouses. They are waiting for documents entitling them to food rations from the WFP.

The line is part of the famous British-financed Benguela railway, which began running 100 years ago but which has long since ground to a halt. Wagons have plates on them with inscriptions such as: "Built by Metropolitan Cammell Carriage Wagon Co Ltd. England 1951." If the railway is rehabilitated, it could transform the lives of the people who live along it. They could send agricultural produce to Luanda and the cities of the coast, and bring in almost everything they need to rebuild their lives. Officials say that the railway could be up and running within a couple of years, but, of course, all this needs money.

The problem for Angola is that the IMF, which provides poor countries with virtually interest-free loans, has refused to lend Angola any money. Reading between the lines of its declarations about the need for financial "transparency" in Angola, the IMF says, to put it crudely, that it will not throw good money after bad. It has calculated that every year about $1bn of oil money cannot be accounted for. In other words, IMF officials believe that the small number of people who run the country simply steal the cash. Indeed, more than $600m is currently blocked by the Swiss judicial authorities in private bank accounts belonging to Angolans who are close to the president.

This does not mean that Angola cannot raise funds. It can and is, by borrowing at high commercial rates of interest raised against future oil production. But, so far, few Angolans have seen any of the proceeds, and foreign diplomats in the country lament that banks are prepared to lend the government money even when they know that a large slice will simply be siphoned off to private accounts.

Rafael Marques, the head of the Open Society Institute in Angola, is one of the tiny but growing band of civil society activists who are prepared openly to criticise the authorities. He is seething about what is happening to his country. But, he says, very, very slowly, "people are realising that the war was used to advance the personal agendas of the Unita or MPLA guys". Now, he says, elections are being discussed in which President dos Santos may well stand again. "Dos Santos is a robber and we here are trying to work out how a robber can become a decent head of the central bank." At some point in the next few years, he concludes, this system must collapse. "It is a house of cards."

Luckily for those in power, questions about Swiss bank accounts and disappearing oil revenue for ordinary Angolans are like questions to most of us about rocket science. Few Angolans, especially those outside Luanda, even have a radio, so all they know is that the war is over and they want to get home, get planting and find their missing. And much of this is happening. A year ago, there were 2,000 families living in the sprawling camp at Kaluapanda for people displaced by the war, some 40 minutes' drive from Kuito.

Then, they had just emerged from the bush, where they had been trapped for years behind Unita lines, living in rags and with little to eat. At the time, the aid agencies spoke of "the worst malnutrition crisis in Africa in the past decade". Today, the crisis is over. Emergency programmes saved hundreds of thousands of lives, and agriculture is beginning to return to these areas. And yet, for some of the war's victims, the smallest ones, the fear remains.

We have come to find Betu and Beki, now aged six and 11, brothers recently reunited by the Red Cross after they had been separated three months before the death of Savimbi. We meet the boys at a small pond, a mile or so's walk through the bush, where the women of Kaluapanda are washing clothes. We stick rigidly to the path. Angola is one of the most heavily mined countries on earth.

The boys were parted on a December day in 2001 because Beki had been with his father, searching for honey. While they were away, the village was attacked by government troops and Betu, who was four, had been taken away with the rest of the villagers. The government's strategy at the time was to drain Unita areas of people to deprive it of support and shelter.

I want to talk to Betu, but he does not want to talk to me. He is rigid with fright. His mother is dead and the brothers live with their stepmother, Teresa Sebastiao. She laughs. "He thinks you are going to take him," she says.

In Kuito, where in 1993 Unita and the government fought a savage nine-month battle, we explore the ruins. In the wrecked, pink, colonial era bank building, Domingos Castro, who works for the Red Cross here, points to the municipal assembly building across the street. Government forces had used the bank as their base and Unita the assembly. I ask Domingos, who was 15 at the time, how he had managed to stay alive in the encircled government side of town. "I got a gun to survive and go on the batidas - they were columns of soldiers and civilians who went to look for food in the [Unita-held] villages. They took everything, maize, beans, everything. Sometimes there were 700 people, of which 300 or 400 were soldiers, and sometimes only 500 or 600 would come back because the others had been killed in ambushes."

So many were killed here that people lie buried everywhere. A man who was trying to take cover from a sniper behind Domingos's house was killed by a shell, then buried in Domingos's front yard. Domingos takes me to a school that back then had been a military hospital. The ground behind the building is filled with graves, but the area at the front, Domingos says, "is full of arms and legs, which were amputated. We buried my cousin's leg there, in a cardboard box."

More than 7,000 graves, including mass graves, are believed to be dotted across the town, but the local authorities want to start exhuming them and reburying the bodies in a local cemetery, which they hope to make a symbol of reconciliation. We decide to visit a couple of local Unita officials, and I ask Domingos if it makes him angry to meet these people who had once tried to kill him. "No," he replies. "We have to forget, or it will be war again."

Joaquim Sousza Junhor, the town's government administrator, tells me proudly that in the next year 100 new schools will open in the municipality. The government is not paying for them, he says - the local people are building them themselves. "The people are helping to make mud bricks and grass to cover the schools, but the government will pay for teachers, chalks and materials."

While in Kuito, I meet a pastor. I ask what he tells his flock and whether he refers to Angola's missing billions. He is cautious; he does not want his name used as he has been in prison in the past, because, he says, he came from the same area as Savimbi. I ask what Jesus would say if he came to Angola today. "So many people would be condemned because they are indifferent to sufferings of the poor."

While we had been in the bank, we had noticed an old man slapping mud over holes in a tiny cubbyhole-like room. He is Manuel Chieke, aged 54, though he looks at least 20 years older: "I came from Chinguar in 1999, because my wife was sick and needed to go to hospital," he says. "She died last year. I left our baby to the nuns. Sometimes I have to go from house to house to beg or I make stoves that I sell." He has no family left in Chinguar, so does not want to go back. He has children in Luanda, but doesn't know where. He has never heard of the Red Cross tracing service. Two days later, we return with Joaquim Neves Zumba, who works for the tracing department in Kuito.

Joaquim discovers that Manuel has a son who had been sent to Cuba to study. "But, when he came back, he did not want to come home to Chinguar, because of the war," says Manuel. Joaquim is delighted. In Luanda, there are records of all those who went to study abroad and, he says, more than likely the relevant department will know where Manuel's son is. Perhaps this will turn into another success story.

As we go, Manuel asks a favour. "When my wife died, we had only one blanket. But I had to bury her in it. I get so cold, could you help me get another one?"

· The British Red Cross, which supports the ICRC's work in Angola, can be contacted at 020-7201 5060