Violence broke out in impoverished Paris suburbs for the seventh straight night, with rioters clashing with police and leaving a trail of torched cars and vandalized premises.

In Aulnay-sous-Bois in the worst affected area of Seine-Saint-Denis, a police station was briefly besieged by gangs of youths while a gymnasium and a garage were set ablaze and a commercial centre vandalized, a fire service spokesman said.

A total of 40 vehicles, including two buses, were torched before midnight in nine towns in the Seine-Saint-Denis department, a high-unemployment largely-immigrant department, according to local police who made 15 arrests.

Two primary schools were also damaged in the area northeast of the French capital.

Elsewhere a France 2 TV crew were forced by hooded youths to abandon their car, which was then set ablaze by 40 rioters.

The riots were first triggered last Thursday by the accidental electrocution of two youths, aged 15 and 17, who had scaled an electrical relay station's walls to escape a police identity check in Clichy-sous-Bois.

Since then, tensions punctuated by the night-time confrontations have increased in the low-rent suburbs that surround Paris and house many immigrants or descendants of immigrants from France's former African colonies.

The firing of a police tear gas grenade against a mosque in Clichy-sous-Bois during clashes late Sunday also sparked rage in the suburb's large Muslim community.

Increasingly observers are pointing to France's failure to address deep problems of poverty and immigration.

The violence has so shaken authorities that French President Jacques Chirac came forward on Wednesday to call for calm and vowed to investigate the teens' deaths.

"Tempers must calm down," a spokesman quoted him as telling his cabinet.

Chirac warned that "an escalation of disrespectful behaviour would lead to a dangerous situation" and asserted that "there can be no area existing outside the law" in France.

Prime Minister Dominique de Villepin put off indefinitely a trip to Canada originally scheduled for Wednesday to call an emergency meeting of ministers to discuss the problem and attend a parliamentary session in which he called the violence "extremely serious."

He told ministers that "the government will ensure public order and will do so with the necessary firmness."

He said he was counting on Interior Minister Nicolas Sarkozy who cancelled a trip next week to Pakistan and Afghanistan to deal with the situation to "take the necessary measures."

As on the previous night, the violence radiated to other departments ringing Paris.

Dozens more vehicles were set ablaze in the Hauts-de-Seine region west of Paris where another police station was the target of Molotov cocktails. Three people were arrested there.

Meanwhile 40 hooded youths vandalized a commercial centre just 200 metres from the Seine-Saint-Denis police headquarters, in front of which one car was set on fire.

Three traders were slightly injured in the attack which took place as shops were closing.

Mediators called for the immediate withdrawal of police from the troubled areas "to avoid all provocation."

The grievances have been further fuelled by Sarkozy's hardline law-and-order policies.

The interior minister, who is also leader of France's ruling UMP party, has made no secret of his ambition to succeed Chirac in 2007 presidential elections.

Just one week before the riots exploded, he promised a "war without mercy" on violence and petty crime in the suburbs.

The opposition Socialist Party criticized Sarkozy's rhetoric, and accused the government of "creating an explosive situation" in the suburbs.

Observers see the riots as a sign of the growing divisions in French society Muslim immigration, poverty, declining education standards in downtrodden areas and joblessness.

Source: China Daily