By Paul Carrel

BOBIGNY, France (Reuters) - Rioters shot at police and fire fighter crews in the worst night of a week of violence in poor suburbs that ring Paris, as France's conservative government struggled to quell the unrest.

Youths who rampaged on Wednesday night 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.

"It's a dramatic situation. It is very serious and we fear that the events could even get worse tonight," said Francis Masanet, secretary general of the UNSA police trade union.

Rioters torched 177 vehicles and attacked a primary school and shopping centre, local officials said. Four police officers and two firefighters 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.

"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 a fire crew in Saint-Denis," he told a news conference.

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.

Twenty-three people were in custody, he added.

Interior Minister Nicolas Sarkozy, accused by opponents of enflaming passions with his outspoken attacks on the "scum" behind the violence, maintained a conspicuously low profile.

He met Prime Minister Dominique de Villepin for a working lunch but neither man, rivals to lead the right in 2007 presidential elections, spoke out publicly over the escalation in the violence.


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 squabbling within his cabinet over how to handle the disturbances that forced him to cancel a Canada trip.

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 at Socialist attacks, noting crime rose 15 percent during its last 5-year rule. He has sent 2,000 extra police to the areas to help enforce his "zero tolerance" on rioters.

Some leftwing police trade unions have criticised his policies and called for a return of neighbourhood police. One police union official described the unrest as a "civil war" and urged Sarkozy to impose a curfew in the affected areas.

The unrest erupted first in the Clichy-sous-Bois after two teenagers were electrocuted while apparently fleeing police during a local disturbance.

Local prosecutor Francois Molins told reporters police had not been chasing the pair when they clambered into an EDF substation, but he had opened an official probe to further investigate the matter.

(Additional reporting by Kerstin Gehmlich and Jon Boyle)