French police fired tear gas under a rain of projectiles and arrested dozens of people on Saturday as thousands of "yellow vest" anti-government protesters returned to the streets of Paris.

Demonstrators shouted slogans denouncing the police, President Emmanuel Macron and his pension reforms that have triggered the longest French transport strike in decades.

The night before Macron and his wife Brigitte had to be rushed briefly from a Paris theatre after protesters tried to burst in and disrupt the performance. With sirens wailing, riot police drove across the French capital in dozens of vans Saturday to the route where thousands of protesters marched. The police said 32 people had been arrested by the early afternoon.

At times under a hail of projectiles, riot police fired tear gas and stun grenades.

Young people wearing masks shouted "revolution" as tear gas drifted by the Bastille, the square where the French revolution erupted in 1789.

"The street is ours," some protesters chanted. "Macron, we're going to come for you, in your home." Saturday's clashes came on the 45th day of a strike that has hit train and metro traffic and caused misery for millions of commuters in Paris especially.

Trains are becoming more frequent however, and Paris's metro drivers voted to suspend their action from Monday, their union UNSA announced Saturday.

The protests were also the latest of the weekly demonstrations held every Saturday by the yellow vest movement since November 2018, and which have been boosted by opposition to the pension reforms.

Annie Moukam, a 58-year-old teacher, said too many people in France were suffering.

"We're suffocating with this government who wants to put us on our knees," Moukam said.

"It's out of the question that he (Macron) touches our pensions. We have worked all our lives to be able to leave with a dignified retirement," she said. "It's exactly that that he is challenging." Macron's reforms aim to forge a single pensions system from the country's 42 separate regimes.

The various systems currently in place offer early retirement and other benefits to some public-sector workers as well as lawyers, physical therapists and even Paris Opera employees.

Critics say the reforms will effectively force millions of people to work longer for a smaller pension.

The transport unions have joined forces with the yellow vests, who accuse Macron of ruling on behalf of an urban elite while ignoring people in the provinces and the countryside, many of whom struggle to make ends meet.

The unions are looking for a second wind as their movement starts to flag, with the proportion of striking workers at national railway operator SNCF falling to less than five percent on Friday.

The Louvre in Paris, the world's most visited museum, reopened on Saturday after being shut down by workers opposed to the pension overhaul.

On Friday, hundreds of disappointed visitors had massed outside the Louvre, some hurling insults at strikers who had blocked the entrance.

It was the first time since the strike began on December 5 that the museum had shut completely, although it was forced to close some galleries last month.

There was no sign of an end to the strike at the Paris Opera, which has lost 14 million euros ($15 million) with the cancellation of 67 performances.

The Paris Opera orchestra on Saturday gave renditions of Carmen and other works to Parisians and tourists on the steps of the Palais Garnier to show support for the strike.

Under a stream of confetti, they finished with "La Marseillaise," the national anthem. Supporters chanted "Vive la greve!" (Long live the strike.)

Macron's staff said the president and his wife were able to return to the play, "The Fly," when police were able to prevent protesters entering the renowned theatre Bouffes du Nord.

But authorities kept in custody overnight Friday Taha Bouhafs, the journalist who tipped off protesters about the presence of the Macrons at the theatre, a judicial source said.

Bouhafs, who was watching the same play, was detained on charges of "participating in a group formed to commit violence or cause damage," the source said.