Rioters clashed with police in the eastern French city of Grenoble on Sunday night after two teenagers died in a collision with a coach while they were being chased by police.
The teenagers, aged 17 and 19, ran into a coach on a bridge as they fled by scooter late on Saturday evening.
Neither had been wearing a helmet, reports say.
Youths set up barricades and threw petrol bombs at police and set fire to cars in the centre of the city.
Tensions were high for a second night running on Sunday in the Mistral district of the city where the teenagers lived.