Police reinforced their presence after scattered skirmishes with youths in the southern Paris suburb of Grigny on Saturday, amid heightened alert against a new bout of violence.
But police said the first anniversary marking the start of France's most serious riots in decades pass without major incident on Friday, with six policemen suffering minor injuries and two buses torched overnight. Four thousand extra police were drafted into Paris suburbs with high immigrant populations and 47 people were arrested, 34 of them in areas around the capital.
On Friday, masked youths in the north-eastern Paris suburb of Blanc-Mesnil attacked the buses, forcing the passengers to get off before setting fire to the vehicles.
Police confronted youths in Clichy-sous-Bois, the poor north-eastern Paris suburb from where riots spread last year to other areas of the country.
"It was a relatively calm night," a police spokesman said. The interior ministry said there had been "few incidents".
On Saturday, a policeman was lightly injured as dozens of youths attacked security forces at a Grigny housing project, police officials said.
"The police were called around 1415 for apparent vehicle burnings that had never taken place," one official said. Clashes followed. But calm returned by mid-afternoon to the Grande Borne housing project, and residents went about their affairs.
Rocks and debris from tear gas containers littered the project's entrance, however, and police took away two supermarket carts piled high with stones.
Grigny's gritty housing project has been the recent target of youth unrest.
Youngsters torched a bus last on Sunday, causing no injuries, and police and other cars were stoned on Wednesday.
On Friday, a total of 277 vehicles were set on fire across the country, according to the Le Monde newspaper, but the authorities refused to confirm the figure.
That figure was only three times higher than the number of vehicles torched on a normal day in France.
Police said police and youths had also clashed in the north-eastern city of Reims and in Toulouse in the south-west.
Last year's riots were sparked by the deaths in Clichy-sous-Bois of Zyed Benna, 17, and Bouna Traore, 15, both from families of African descent.
They were electrocuted as they hid in an electricity sub-station while fleeing from police.
Riots broke out in Clichy-sous-Bois that night, quickly spreading to dozens of suburbs in the Paris region and other French cities.
Night after night for three weeks, mainly north African youths clashed with police, torching more than 10,000 cars and firebombing 300 buildings in around 275 towns, until order was officially restored on November 17.
On Friday, more than 1,000 people made a silent march past the spot where the two teenagers died.
The mayor of Clichy, Claude Dilain, told the crowd: "Once again, France and the world are watching us. We need the calm, dignity and courage that are visible here to prevail. Let us show them who we really are."
But police and mayors have warned that the conditions that led to the riots remain firmly in place in poor out-of-town neighbourhoods plagued by unemployment of 30 to 40 percent.