Rioters shot at police and fire crews in the worst night in a week of violence in poor Paris suburbs as France's conservative government struggled to respond to the unrest.
Youths rampaged in nine poor 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.
"It's a dramatic situation. It is very serious and we fear that the events could even get worse tonight," said the secretary general of the UNSA police trade union.
Prefect Jean-Francois Cordet, the government's top official in the Seine-Saint-Denis region, confirmed rounds had been fired at police and fire crews in three separate incidents.
"Four live bullets were fired. Two shots were fired at La Courneuve against police. One shot was fired at Noisy-le-Sec against fire crews, and one shot was fired against fire crew in Saint-Denis," he told a news conference.
Mr Cordet did not say what sort of weapon had been fired, but local police reportedly recovered shotgun cartridges from the scene at La Courneuve.
No one was reported as hurt in the shootings, which marked an escalation in the level of violence that left 177 charred vehicles and damaged a primary school and shopping centre.
Mr Cordet said four police officers and two fire fighters were hurt, including one who was burnt on the face by a Molotov cocktail. Twenty-nine people were detained, and 23 remained in custody, he added.
French prime minister Dominique de Villepin discussed the crisis with elected officials from the
affected areas as the government struggled to respond to the violence and the opposition taunted the conservative's much-vaunted crime record.
He will meet Nicolas Sarkozy, his potential rival to lead the right in 2007 presidential elections, in a display of unity after government squabbling over how to respond to the violence.