Protesters angry with President Emmanuel Macron blocked access to an airport terminal, sat on train tracks and threw objects at a police station during demonstrations across France.
Police fired tear gas at campaigners in Nantes and used a water cannon in Rennes as projectiles caused a brief fire in the yard of a police station.
Violent protests have been held in opposition of Macron’s pension age reform, which will see the national retirement age increase from 62 to 64.
Roissy-Charles De Gaulle airport was hit with strikes by workers and near Toulouse in the southwest, burning piles of debris blocked traffic on a highway and sent plumes of smoke into the sky.
Nine days of strike action have been held nationwide in France
“There is a lot of anger, an explosive situation," the leader of the hardline CGT union, Philippe Martinez, said at the start of a rally in Paris.
Macron broke weeks of silence on the new policy to say he would stand firm and the law would come into force by the end of the year.
He compared the protests to the storming of the US Capitol in January 2021.
Voters were further angered by the government's decision last week to push the pension changes through parliament without a vote.
"I'm on strike to protest against the pensions reform, but also against what is happening in the government," 27-year-old Air France programming officer Lucile Bidet said at a rally in Nantes.
"They're not listening to the people anymore."
"He's the one setting the country on fire," the CGT's Celine Verzeletti told France Inter radio station.
On Thursday, electricity output was cut as unions raised pressure on the government to remove the law.
Macron broke weeks of silence on the new policy to say he would stand firm
The civil aviation authority also confirmed that flight services will continue to be reduced at the weekend.
Paris and other cities have seen seven nights of demonstrations with rubbish bins set alight and clashes with police.
"The street has a legitimacy in France. If Mr Macron can't remember this historic reality, I don't know what he is doing here," 42-year-old entertainment show worker Willy Mancel said at the Nantes rally.
Labour Minister Olivier Dussopt said the government was not in denial about the problems but wanted to move on.