Violence marred the end of a day of mostly peaceful demonstrations across France against a new labour law.
Police in Paris charged at rioters and used tear gas in an attempt to disperse the crowds.
A number of cars were set alight by the rioters.
More than 100 arrests were made, and dozens of people were injured.
Earlier, hundreds of thousands of people demonstrated without incident.
Paris saw the biggest rally, and the largest since protests began earlier this month.
It passed off largely with good humour, with this couple seen dancing in front of the police.
But as the march broke up some demonstrators threw missiles towards the police.
In the northern city of Lille, demonstrators attempted to erect barricades in the streets.
Riot police in the city swooped to make arrests, charging the demonstrators and using teargas.