Protesters have thrown projectiles at police and set cars and rubbish bins ablaze in a bleak area of the Paris suburbs where tensions have risen over alleged police brutality in the arrest of a local man.
A policeman has been placed under formal investigation for suspected rape and three others for unnecessary violence on 2 February during the arrest of the 22-year-old man in Aulnay-sous-Bois outside the French capital.
Cars and rubbish bins were torched in a night of violence on 7 February and disturbances resumed today.
The Paris police prefecture said some 2,000 people gathered peacefully in Bobigny, adjacent to Aulnay-sous-Bois, in support of the arrested man, identified by his first name, Theo, before some people in the crowd began hurling crude projectiles at riot police.
"Several vehicles, including a media truck, were set on fire and police officers had to intervene to rescue a young child trapped in a burning vehicle," a prefecture statement said.
The predominantly immigrant district is one of several where riots erupted in 2005 after two youths were fatally electrocuted in a power station where they took cover after fleeing arrest.
That incident sparked three weeks of rioting in which 10,000 cars and 300 buildings were set on fire, prompting then interior minister Nicolas Sarkozy to declare a state of emergency and drawing worldwide attention to the contrasts between Paris and the economically deprived suburbs that surround it.
Earlier, four people were arrested in the Mediterranean port city of Marseilles on the sidelines of a march in support for Theo, a police source said.