Hundreds of thousands of workers have taken take part in strike action across France on Thursday, after trade unions called for a day of protests against budget cuts.
Organisers said one million people turned out, while the interior ministry put that number at 500,000, with 80,000 police officers deployed.
Scuffles were reported in the cities of Lyon and Nantes, and in Paris small-scale clashes broke out between police and protesters.
Officers in riot gear used tear gas and shields to disperse crowds in the centre of the capital after some protesters damaged a small number of businesses and buildings.
The strikes come barely a week after Sébastien Lecornu, a close ally of President Emmanuel Macron, was appointed prime minister following the toppling of François Bayrou's government.
Public transport was heavily disrupted on Thursday, with many metro lines in Paris reported shut, while protesters blocked roads and streets in major cities across France.
Students gathered in front of schools and universities in the capital and beyond, blocking entrances and chanting slogans. Around a third of teachers walked out.
Pharmacists were also adhering to strike action in droves, with 98% of pharmacies expected to stay closed.
More than 300 people were detained across France, the interior ministry said.
Unions have called for more spending on public services, higher taxes on the wealthy and for the budget cuts outlined by the short-lived Bayrou government to be axed.
Cyrielle, a 36-year-old IT worker, told the BBC she was striking because 'Macron's economic and social policies don't suit me, nor did Bayrou's budget.' She was taking part in a tightly-policed, large demonstration in central Paris.
Sophie Binet, the leader of one of France's major trade union groups, said: 'We need to be out in force, that's how we gather strength to keep fighting...'
Bruno Retailleau, the outgoing interior minister, warned of strict police action during the protests, stating that police were instructed to make arrests for any slip-ups. Meanwhile, opposition leader Jean-Luc Mélenchon called for disciplined protests to avoid giving the government an excuse for further crackdowns.
These strikes come in the wake of a recent failed budget proposal by Bayrou, aimed at reducing France's high public debt through significant cuts. New Prime Minister Lecornu is yet to establish a clear budget policy and is engaging in talks with opposition parties for potential compromise.
