Italian drivers are being forced to leave their cars at home today Sun and for the next three Sundays in an attempt to reduce air pollution.

After successful experiments in the big industrial cities of Milan and Turin, the Sunday car ban is being extended to urban areas all over the country, including Rome, where the whole city centre will be closed off.

Public transport is to be free all day, as is admission to museums and archeological sites.

Four out five Italians say they are in favour of the ban, although the country has one of the highest rates of car ownership in the world. The environment minister says the experiment will determine whether carless Sundays become a permanent feature of life in Italy.

But the BBC Rome correspondent says that until public transport improves radically, most Italians are unlikely to leave their cars in the garage.

From the newsroom of the BBC World Service