The driver in a crash that killed four cyclists when his car ploughed into them on an icy road received a £180 fine and six points on his licence today.

The lightness of the penalty prompted campaigners to call for a change in the law. It came as official statistics showed a sharp rise in accidents involving cyclists at the start of this year.

Robert Harris, 47, was driving a Toyota Corolla with three defective tyres when he lost control on black ice near his home in Abergele, north Wales, on January 8 this year. The car crashed into a group of 12 members of Rhyl cycling club, who were on a training ride.

Among the four riders killed was 14-year-old Thomas Harland.

The Cyclists Touring Club campaigns and policy manager, Roger Geffen, said: "Our first thoughts are for the families of those killed in this terrible tragedy. It highlights the need for a serious overhaul of road traffic law and the priority given to its enforcement.

"Time and again when people are killed and seriously injured, the message given out by the legal system is that these incidents are nothing more than tragic 'accidents'.

"The victims are disproportionately pedestrians and cyclists, the very forms of transport we most need to encourage for health and environmental reasons."

Mr Harris, a security guard for DIY chain B&Q, pleaded guilty to three counts of driving with defective tyres by post and did not attend the hearing at Llandudno magistrates court today.

Diane Williams, prosecuting, told the court that a police investigation found that Mr Harris's defective tyres were not the cause of the crash.

She said: "The crown took the decision that, in the circumstances, tyre tread is there to displace liquid debris from the road to give a better grip."

"In this situation, the examination has found there was no liquid there; it was black ice. Consequently the defective tyres couldn't have been a contributory factor to the collision."

Llion Williams, chairman of the magistrates bench, fined Mr Harris £60 for each of the counts and endorsed his driving licence with three points for the first two counts, but none for the third.

He said: "We are dealing with this case as we would any case involving defective tyres, where a guilty plea has been entered by post.

Figures from the Department of Transport showed there was a 20% increase in serious or fatal cycle accidents in the first three months of the year.

They showed that 440 cyclists were killed or seriously injured between January and March.

Overall the number of people killed on the roads in this period fell 2% to 740.