About 100 cars were torched nationwide, half of them in the Paris region, police officials said. The figure was higher than usual, police say between 30 and 50 cars are normally burned weekly.
Paris' transport authority curtailed bus service in the Seine-Saint-Denis region north of the capital, which is home to thousands of immigrants and their French-born children.
France was bracing for a replay of violence in mostly poor suburbs on the one-year anniversary of when two teenagers died in what they thought was a police chase in the town of Clichy-sous-Bois.
One bus was engulfed in flames in the nearby town of Le Blanc Mesnil, as firefighters deployed to douse the blaze at the foot of a high-rise housing project.
"What happened is four guys attacked Bus 346," said witness Thierry Ange, 19. "They made everyone get off, then they hit a woman and dragged out the bus driver by his tie," then the youths torched the bus with a petrol bomb in a bottle, he said.
The blackened carcass of another bus that was burned earlier stood across town in Le Blanc Mesnil. Two armed men forced passengers off the bus in the earlier attack, police said.
The national police said 50 groups of extra officers and riot police, in total about 4,000 extra officers have been deployed across the country to cope with a possible resurgence of violence.
Flaming cars became a symbol of the rioting last year, which jolted France into recognising a failure to give equal opportunities to many minorities, especially those of Arab and African origin and France's 5 million-strong Muslim population.
The outburst of anger at the accidental deaths of the two teenagers, who died electrocuted in a power substation while hiding from police last October 27, grew into a broader challenge of the French state.
The boys' families and Clichy-sous-Bois Mayor Claude Dilain called for calm today.
Several hundred people marched silently through Clichy-sous-Bois, northeast of Paris, in honour of Zyed Benna and Bouna Traore.
Adolescent boys in hooded sweat shirts made up a large part of the mixed-race crowd, their heads bent as prayers were read in Arabic and French.
Clichy-sous-Bois has no police station, so officers patrolling the area have to come from other areas and consequently have no connection to residents. There is no public transport and few families own cars, leaving most people virtually trapped.
Unemployment among its 28,000 residents is well above the 9 percent national average at 23.5 percent, and goes up to 32 per cent for those between the ages of 15 and 24, according to the newspaper, La Croix.