Clashes have broken out between police and protesters as “yellow vest” demonstrators and labour unions held a traditional May Day rally.
Dozens of people were injured and more than 300 arrested, as so-called “black block” protesters in dark clothes and face masks also took to the streets.
Some protesters smashed shop windows and threw projectiles at the police, who responded with tear gas and water cannon.
It follows months of demonstrations by the “yellow vests” or “gilets jaunes”, whose original protests about fuel prices have expanded to wider complaints about economic inequality.
French President Emmanuel Macron has made a series of concessions to the movement – most recently with a wave of tax cuts.