More than 1 million people demonstrated across France on Thursday against unpopular pension reforms, and violence erupted in some places as unions called for new nationwide strikes and protests next week, coinciding with King Charles III's planned visit to France.

The Interior Ministry said the march in Paris — marred by violence, as were numerous marches elsewhere — drew 119,000 people, which was a record for the capital during the pension protests. Polls say most French oppose President Emmanuel Macron's bill to increase the retirement age from 62 to 64, which he says is necessary to keep the system afloat.

Building on the strong turnout, unions swiftly called for new protests and strikes on Tuesday when the British king is scheduled to visit Bordeaux on the second day of his trip to France. The heavy wooden door of the elegant Bordeaux City Hall was set afire and quickly destroyed Thursday evening by a members of an unauthorized demonstration, the Sud Ouest newspaper said.

Nationwide, more than a million people joined protest marches held in cities and towns around the country Thursday, the ministry said.

Interior Minister Gerald Darmanin, visiting police headquarters Thursday night as fires still burned in some Paris neighborhoods, gave assurance that security “poses no problem” and the British monarch will be “welcomed and welcomed well.”

He said there was “enormous degrading” of public buildings and commerce Thursday, “far more important than in precedent demonstrations.”

“There are troublemakers, often extreme left, who want to take down the state and kill police and ultimately take over the institutions,” the minister said.

The demonstrations were held a day after Macron further angered his critics by standing strong on the retirement bill that his government forced through parliament without a vote.

“While the (president) tries to turn the page, this social and union movement ... confirms the determination of the world of workers and youth to obtain the withdrawal of the reform,” the eight unions organizing protests said in a statement. It called for localized action this weekend and new nationwide strikes and protests Tuesday.

Strikes upended travel as protesters blockaded train stations, Charles de Gaulle Airport in Paris, refineries and ports.

In Paris, street battles between police and black-clad, masked groups who attacked at least two fast food restaurants, a supermarket and a bank reflected intensifying violence and drew attention away from the tens of thousands of peaceful marchers.

Police, pelted by Molotov cocktails, objects and fireworks, charged multiple times and used tear gas to disperse rioters. A haze of tear gas fumes covered part of the Place de l'Opera, where demonstrators converged at the march's end. Darmanin said radicals numbered some 1,500.

Read more: Nearly 1 million French march in 4th day of pension protests

Violence marred other marches, notably in the western cities of Nantes, Rennes and Lorient — where an administrative building was attacked and the courtyard of the police station was set afire and its windows broken — and in Lyon, in the southeast.

Thursday's nationwide protests were the ninth union-organized demonstrations since January, when opponents still hoped that parliament would reject Macron's measure to raise the retirement age. But the government forced it through using a special constitutional measure.

In an interview Wednesday, Macron refused to budge from his position that a new law is necessary to keep retirement coffers funded. Opponents proposed other solutions, including higher taxes on the wealthy or companies, which Macron says would hurt the economy. He insisted the government’s bill to raise the retirement age must be implemented by the end of the year.

The Constitutional Council must now approve the measure.

“We are trying to say before the law is enacted ... that we have to find a way out and we continue to say that the way out is the withdrawal of the law," the chief of the moderate CFDT trade union, Laurent Berger, told The Associated Press.

High-speed and regional trains, the Paris metro and public transportation systems in other major cities were disrupted. About 30% of flights at Paris Orly Airport were canceled.

The Eiffel Tower and the Versailles Palace, where the British monarch is to dine with Macron, were closed Thursday due to the strikes.

Violence, a recurring issue at protests, has intensified in recent days. Darmanin said that 12,000 security forces were in the French streets Thursday, with 5,000 in Paris,

The Education Ministry said in a statement that about 24% of teachers walked off the job in primary and middle schools on Thursday, and 15% in high schools.

At Paris' Gare de Lyon train station, several hundred strikers walked on railway tracks to prevent trains from moving, brandishing flares and chanting “and we will go, and we will go until withdrawal" and “Macron, go away.”

Read more: Anger spreads in France over Macron's retirement bill push

"This year perhaps maybe our holidays won’t be so great," said Maxime Monin, 46, who stressed that employees like himself, who work in public transport, are not paid on strike days. "But I think it’s worth the sacrifice.”

In the northern suburbs of Paris, several dozen union members blocked a bus depot in Pantin, preventing about 200 vehicles from getting out during rush hour.

Nadia Belhoum, a 48-year-old bus driver participating in the action, criticized Macron’s decision to force the higher retirement age through.

“The president of the Republic ... is not a king, and he should listen to his people," she said.