At Aulnay-sous-Bois, at least 15 cars were torched as youths hurled stones and firebombs. Police fired rubber bullets and arrested 34 people.

Although the initial flashpoint of Clichy-sous-Bois stayed calm, trouble spread across much of north-east Paris.

Unrest has flared since two north African boys died. Local people say they had been fleeing the police.

French Prime Minister Dominique de Villepin and Interior Minister Nicolas Sarkozy have delayed trips abroad to try to calm the situation.

Both met relatives of victims, police officials and community leaders on Tuesday in an effort to calm tensions. But fresh violence broke out even as the pair opened talks.

War of words

As many as 69 cars were reportedly set on fire in nine towns in the Seine-Saint-Denis region, home to many impoverished communities.

Correspondents say anger grew after a tear gas canister was hurled into a mosque in Clichy on Sunday night. Anger has also been fuelled by the mass arrests.

Mr Sarkozy, criticised for his description of the rioters as a "rabble", has repeated his condemnation.

"I speak with real words," Mr Sarkozy, who has cancelled a visit to Afghanistan and Pakistan next week, told Le Parisien newspaper.

"When you fire real bullets at police, you're not a 'youth,' you're a thug."

Prime Minister Dominique de Villepin, who has called for calm, has delayed a trip to Canada to try to ease tensions.

The pair have been accused of playing politics with the situation in an effort to win favour ahead of a presidential campaign in 2007.

On Tuesday, the opposition Socialist Party accused Mr Sarkozy of tarnishing the image of France with his comments.

Cars torched

Unrest flared in Clichy after two teenage boys were electrocuted on Thursday at an electricity sub-station.

Local people insist they were fleeing from police and scrambled in to hide. Police say they were not chasing the boys.

An official investigation is under way.

Clichy saw five successive nights of confrontation between police and young people from the mainly North African Muslim communities in the north-eastern suburb.

Unemployment and social problems are rife in many of France's poorer suburban areas.

Police have reported sporadic incidents involving mobile groups of youths in the Val-d'Oise, Seine-et-Marne, Hauts-de-Seine and Yvelines regions of Paris.

Four people were arrested for throwing stones at police in Bondy, where 14 cars were burned, the Associated Press quoted officials as saying.