Cars and lorries were yesterday banned from more than 100 towns and cities in Italy, including Rome and Milan, in an effort to cut pollution.

Partial bans on cars and lorries have been imposed in many areas in recent days, after calm weather allowed smog to build up. But with no improvement in sight, mayors opted for the one-day ban.

"We had no alternative," Walter Veltroni, the mayor of Rome, was quoted as saying. All non-essential traffic was banned from inner Rome from 10am to 5pm yesterday.

However, the Italian environment minister, Altero Matteoli, told Il Messaggero newspaper: "Forcing people to walk once in a while is of little use." He said people should instead be encouraged to scrap their old vehicles and buy less polluting ones.