French police have arrested more than 250 people following fresh riots in and around Paris and other parts of France.
The deaths of two teenagers of African origin triggered the unrest
Nearly 900 cars were burnt on the ninth consecutive night of unrest in immigrant-dominated areas near Paris, despite a heavy police presence.
Nurseries and a school were burnt overnight and unrest spread to Nice, Lille, Marseille and Toulouse.
Hundreds of people have heard a call for calm at a rally in one of the Paris suburbs worst hit.
The mayor of Aulnay-sous-Bois, Gerard Gaudron, made the appeal to marchers outside a fire station which had come under attack.
But youths at the rally in the suburb's rundown Mitry estate predicted violence would continue until tough-talking Interior Minister Nicolas Sarkozy resigned.
Muslim and Christian leaders were expected to join the march along with the families of the two youths whose deaths triggered the unrest.
Bouna Traore, aged 15, and Zyed Benna, 17, were accidentally electrocuted at an electricity sub-station in Clichy-sous-Bois, near Paris.
Local people say they were fleeing police - a claim the authorities deny. Inquiries are under way.
During Friday night's unrest rioters tended to avoid direct clashes with police, but arson attacks were widespread:
- Two nurseries, one in Yvelines and another in Bretigny-sur-Orgeand, were set on fire along with a school in Seine-et-Marne, the French news agency AFP reports
- A blaze in an underground car park in Suresnes, Hauts-de-Seine, left at least 36 vehicles destroyed
- An emergency services vehicle was attacked and burnt out in Meaux, Seine-et-Marne
- Several car torchings were reported in the cities of Dijon, Marseille and Rouen, as were violent attacks in Nice, Lille and Rennes.
Arsonists destroyed 897 vehicles overnight - with 656 burnt in the area around Paris - Paris chief prosecutor Yves Bot said, while police said they had arrested 253 people.
Rivals Mr Sarkozy and Mr de Villepin are trying to present a united front
Some 1,300 police were deployed in the Seine-Saint-Denis area alone on Friday.
In the nearby area of Clichy-sous-Bois, several Muslim groups intervened and helped to calm the trouble, the BBC's Alasdair Sandford in Paris reports.
Prime Minister Dominique de Villepin has called a meeting of eight ministers for Saturday afternoon to "assess the evolution of the situation in the sensitive urban areas".
The interior minister told police officers on Friday evening that the riots were organised and the key to ending them lay in making arrests.
Many residents say repressive policing has heightened a sense of injustice, with officers systematically stopping and searching young blacks and North Africans in particular, our correspondent says.
'We have been heard'
Mr Sarkozy's much-quoted description of urban vandals as "rabble" (racaille) a few days before the riots began is said by many to have already created tension.
Reports of a police tear gas grenade hitting a mosque during the riots further inflamed feelings.
Some foreign governments - including the US - have advised their citizens to steer clear of the suburbs.
Mr de Villepin is trying to launch an action plan for the affected Paris suburbs, which are poor, largely immigrant communities with high levels of unemployment.
He held a conference with youths from urban areas hit by the unrest on Friday.
"We get the impression that we have been heard," Anyss, a student from Bondy, told AFP afterwards, adding that Mr de Villepin "was genuinely seeking to deal with the problems".
Mr de Villepin has pledged to restore order following criticism of the government's failure to end violence.
But he came under fire from a group of around 30 mayors and other elected officials from the affected areas, who said this was no time for a plan.
"All we need is one death and things will get out of control," said Jean-Christophe Lagarde, mayor of Drancy.
Clichy-sous-Bois: Two teenagers die in electricity sub-station on 27 October. Successive nights of rioting follow rumours they were fleeing police. A number of people arrested or injured.
Aulnay-sous-Bois: A flashpoint after violence spread from Clichy. Shots fired at police and cars and shops set ablaze. Further trouble in eight nearby suburbs, with more shots fired at police.
Elsewhere in Paris: Reports of incidents in towns in the suburban departments of the Val-d'Oise, Seine-et-Marne and Yvelines. Reports of petrol bombs thrown at a police station in the Hauts-de-Seine.
Elsewhere in France: Rouen, Lille, Toulouse, Nice and Marseille all see violence on Friday night.