Rioters shot at police and fire fighter crews in the worst night of a week of violence in poor suburbs that ring Paris prompting France's prime minister on Thursday to vow to restore law and order.
Youths who rampaged overnight left a trail of burnt cars, buses and shops in nine suburbs north and east of Paris, home to North African and black African minorities frustrated at their failure to get jobs or recognition in French society.
Prime Minister Dominique de Villepin condemned the violence and said restoring order was his "absolute priority".
"I refuse to accept that organised gangs are laying down the law in certain neighbourhoods ... Law and order will have the last word," he told senators.
Rioters torched 177 vehicles and attacked a primary school and shopping centre, local officials said. Four police officers and two fire-fighters were hurt, including one with facial burns from a Molotov cocktail.
Prefect Jean-Francois Cordet, the government's top official in the Seine-Saint-Denis region, confirmed shots had been fired at police and fire crews in three separate incidents.
Cordet did not say what sort of weapons had been fired but media said local police recovered shotgun cartridges from the scene at La Courneuve. No one was reported wounded.
Francis Masanet, secretary general of the UNSA police trade union, said: "It's a dramatic situation. It is very serious and we fear that the events could even get worse tonight."
Interior Minister Nicolas Sarkozy, accused by opponents of enflaming passions with his outspoken attacks on the "scum" behind the violence, said 41 people had been detained overnight, and 143 in the past week.
"Faced with the seriousness of these events there is only one political line ... firmness and justice," Sarkozy said.
"Firmness without justice, is extremism. Justice without firmness, is laxity. Our policy ... is to be firm and fair," he told senators.
At a supermarket in Bobigny's shopping centre, staff swept up broken glass and worried about the future.
"If this continues, I'll have to close. Clients are afraid. There's normally lots of people here at this time of the day," said a local cobbler who did not want to be named.
"It's because of the police that this is going on," said one black youth who did not want to be identified. "They are too violent. That's not what their job is."
Governments across Europe have been confronted with violence in deprived inner city areas, and the unrest in France comes despite Sarkozy's anti-crime drive led in the wake of President Jacques Chirac re-election in 2002, won on law and order issues.
Villepin has struggled to end cabinet squabbling over how to handle disturbances that forced him to cancel a Canada trip. Moscow warned Russians against visiting Paris suburbs.
The ruling Union for a Popular Majority is split between a pro-Sarkozy camp and rivals who support Chirac and Villepin, handing the opposition Socialists a rare chance to beat the conservatives over their much-vaunted record on crime. "When you see what's gone on over the past three years, when neighbourhood police have been dismantled ... I think there's another failure to be noted," Socialist leader Francois Hollande said on French radio.
Sarkozy has scoffed that crime rose 15 percent when the Socialists were last in office and says 2,000 more police will help enforce his "zero tolerance" of rioters.