Protests broke out in neighbourhoods north of Paris after a 24-year-old man was taken into police custody, with relatives claiming that the man had been the victim of police violence.
Two investigations were opened after a night of protests during which six police officers were slightly injured, newspaper Le Parisien reported. Police spokeswoman Karine Lejeune told broadcaster BFMTV that the man had suffered an illness.
But family members told the broadcaster that the man, taken into police custody for petty crime, had been the victim of police violence and said he had been hit in the head by police.
Amateur videos of the protests show fires on the streets in the bordering neighbourhoods of Beaumont-sur-Oise and Persan.