French riot police detained 27 people following a night of violent clashes in central Paris after worker and student protests around the country continued, demanding the withdrawal of a labour reform bill.
Riot police fired tear gas at demonstrators who believe the reform threatens workers' rights. Several protesters were injured during the clashes.
Police attempted to clear a group of about 150 youths from Place de la Republique square where clashes erupted.
"These are largely people coming looking for a fight," Interior Ministry spokesman Pierre-Henry Brandet said.
French Interior Minister Bernard Cazeneuve announced on Thursday that at least 100 protesters were detained country-wide.
"I call on the organisers of these demonstrations to condemn with the same firmness that I do the unrest caused by this handful of thugs," the minister said in the city of Lyon.
The head of France's large General Confederation of Labour (CGT), Philippe Martinez, said the reform would give bosses greater freedom to determine terms of pay, rest and overtime rates.
"We want it withdrawn as long as the goal means the law is no longer the rule, and that every company can opt out on work time or overtime rates. That's unacceptable," he said.
Opponents of the reform say it will increase job insecurity for the young and increase France's 35-hour working week.
Protests against the labour reform began on March 9, leading to massive demonstrations on March 31 that brought out 390,000 people on to the streets, according to official reports, while the rally's organisers said the number was 1.2 million.