Rioters burnt almost 900 vehicles in the Paris region and large provincial cities like Strasbourg, Rennes, Toulouse and Lille, officials said, the highest total since the deaths of two youths while apparently fleeing police sparked the disturbances.
The riots have been seen as a reaction by youths of North African and black African origin angry over racism, unemployment and exclusion from wider French society.
Police arrested 203 suspects overnight and drafted in a helicopter to film events that judicial officials say are being organised over the Internet and by mobile phone.
“Without question what is taking place bears all the hallmarks of being coordinated,” Yves Bot, the Paris public prosecutor, told Europe 1 radio.
“The way things are organised is in response to a strategy ... with mobile tactics employed by youths, who turn up on scooters, throw a lighted bottle at a vehicle and then leave.”
In Meaux, a town east of Paris whose mayor is government spokesman Jean-Francois Cope, youths threw molotov cocktails at paramedics, whose patient was taken to hospital under police escort.
Prime Minister Dominique de Villepin, who has struggled to halt cabinet squabbles, restore order and defuse tensions, summoned key ministers to his offices on Saturday to formulate a political response.
In Aulnay-sous-Bois, a rundown Paris suburb hit by the unrest, local Catholic, Protestant and Muslim leaders organised a silent march.
“It’s a game. The kids are out there because all they want to do is trash stuff,” said one local cafe owner who did not wish to be identified.
Insurance companies quoted by French media put at 7 million euros ($8.44 million) the cost of more than a week of rioting that has left ministers squabbling in public and forced Villepin to cancel a trip to Canada.
The prime minister has vowed to restore order but said he is ready for dialogue, meeting young residents from troubled neighbourhoods late on Friday. He plans to publish an action plan targeting 750 tough districts by the end of the month.
“There needs to be better communication between the state, the police and youth, because they feel they are undervalued, that they are third- or fourth-rate French people, not even second-rate, because they really live in conditions worthy of a developing country,” said one woman who attended the meeting.