More clashes broke out between protesters and French police as thousands of people went out on the streets to express their disapproval of President Emmanuel Macron's pension reform.

The day of nationwide protests and strikes called by unions is the tenth since mid-January against the law, which includes raising the retirement age from 62 to 64.

The movement, has turned into a major challenge for Macron who won a second term in elections last year and, presents the biggest crisis of his second mandate.

Some 13,000 police personnel were deployed nationwide on Tuesday after last Thursday saw the most violent clashes yet between protesters and security forces.

French police have been accused of using excessive force – both by protesters and rights bodies – which has further fuelled anger among demonstrators.

In eastern Paris, police fired tear gas and launched a charge after some masked protesters, dressed in black, raided a grocery store and engaged in arson as the march closed in on Place de la Nation.

Police said at least 27 people were arrested in the capital by the afternoon.

Threw projectiles

Protesters delayed trains at Gare de Lyon, one of the busiest stations in Paris, as they walked on rails and lit flares in what they called a show of solidarity for a railway staffer who lost an eye during a previous protest.

In the western city of Nantes, protesters threw projectiles at security forces who fired back tear gas, as per an AFP reporter. A bank was set on fire as were rubbish bins around the city.

Police deployed water cannons in the southeastern city of Lyon, and used tear gas in the northern city of Lille after protesters caused damage including vandalizing a bus stop.

Rubbish collectors in Paris are suspending a three-week strike from Wednesday that has seen thousands of tonnes of garbage accumulate in the capital, said the CGT union.

But it said the move was to allow workers' coordination to "go on strike again even more strongly" as fewer workers were now striking.

Nearly two weeks after Macron forced the new pensions law through parliament using a special provision, unions have vowed no let-up in mass protests to get the government to back down.

A state visit to France by Britain's King Charles III, which had been due to begin on Sunday, was postponed because of the unrest.

Political talks

Macron on Monday held crisis talks with Prime Minister Elisabeth Borne, other cabinet ministers and senior lawmakers at the Elysee Palace.

"We need to continue to hold out a hand to the unions," a participant in the meeting quoted Macron as saying, although the president rejected any revision of the pensions law.

Borne has scheduled talks over three weeks with members of parliament, political parties and local authorities, while still hoping to meet union leaders.

Laurent Berger, head of the moderate CFDT union, called for the appointment of a mediator between unions and the government as "a gesture in favour of cooling off, and finding a way out."

Hard-left CGT union leader Philippe Martinez said, "The aim is the withdrawal" of the pensions law.

But government spokesman Olivier Veran said the law was no longer up for discussion. "It's in the past now," he said.

'Nothing is changing'

The French Interior Ministry put Tuesday's turnout at around 740,000 protesters nationwide, down somewhat on the 1.09 million who took to the streets last Thursday.

The CGT union said over 2 million protested, also down in its estimation of 3.5 million on March 23.

Youngsters were prominent in Tuesday's protests, with many blockading universities and high schools.

Jo Zeguelli, 19, a student at the Sorbonne university in Paris said, "Nothing is changing. Macron does not seem like he is listening to us."

In Toulouse, Paul Castagne, 26, a doctoral student in ecology said he feared "what the government is trying to do is let the situation deteriorate and play on people's weariness."

Mass transit in Paris was heavily affected, with traffic both on metros and suburban trains disrupted.

On Monday, workers blocked entry to the Louvre in Paris, the world's most visited museum, forcing its closure.

As on previous strike days, the Eiffel Tower in Paris and the Palace of Versailles outside the capital were also shut on Tuesday.