Firemen rushed to put out fires in the suburb of Val d'Oise after youths late on Friday torched some 10 cars and two buildings, one of them a bakery. 
   
In another suburb, Epinay-sous-Bois, about 40 youths, wearing hoods to hide their faces, ransacked around 10 cars, police said.
   
Rioting by youths, many of whom are Muslims of North African and black African origin, has partly been stoked by their frustration at high unemployment and the perception they lack economic opportunities.
   
The latest outbreak of violence came in defiance of a high-profile police presence.
   
About 1300 officers deployed in Seine-Saint-Denis, the area worst hit in more than a week of disturbances and where the violence first began last week after two teenagers of African origin died while fleeing the police.
   
More officers were deployed in other suburbs where unrest had broken out, national police said, adding that the units were more mobile than previously.
   
The violence, which first began in Seine-Saint-Denis, has escalated this week and spread overnight between Thursday and Friday to a few other towns in France - Rouen in northern France, Dijon in the east and Marseille in the south.
   
This has put mounting pressure on Prime Minister Dominique de Villepin's government to restore order without alienating minority and underprivileged groups.