Riot police patrol the northern Paris suburb of Villiers-le-Bel, 27 Nov 2007

Riots have broken out for a third straight night in a northern Paris suburb despite heavy police presence.

Rioters burned several cars in Villiers-le-Bel Tuesday night, where the deaths of two young people whose motorbike collided with a police car Sunday set off the violence.

The riots have also spread to the southern French city of Toulouse, where police say 10 cars and a library were set on fire.

Police say the violence has injured 120 officers since Sunday. Four of the officers near Paris were seriously wounded by buckshot from hunting rifles.

French Prime Minister Francois Fillon calls the violence unacceptable and says those who shoot at and beat up policemen must be treated as criminals.

Some witnesses to Sunday's collision between the motorbike and police car say the officers left the scene without helping the victims. French officials say the officers remained there until help arrived.

This week's riots are reminiscent of the 2005 youth violence outside Paris and other cities against unemployment, living conditions, and what the rioters call discrimination against young Muslims and those of North African descent.

Some information for this report was provided by AFP, AP and Reuters.