Britain's head of state, King Charles III, has cancelled a visit to France, amid growing unrest over the French government's pension reforms. 

The king and the queen consort, Camilla, were due to visit France from March 26-29, in what would have been the monarch's first overseas visit since he became king last year.

France has been preparing for the state visit, with a banquet due to be held at the lavish and sprawling Palace of Versailles on March 27.

The images of a President and a King dining in fine dress in a golden banqueting hall while millions of protesters continue with their demonstrations, which are increasingly turning more violent, was decided by the British and French government to have "not made sense."

On Friday, Emmanuel Macron said that the visit would take place when the situation "is calmer," calling the postponement "common sense."

The next day of mass mobilization against the government plans to raise the retirement age from 62 to 64 is due to be March 28 - when the King was set to have caught a train from Paris to Bordeaux.

On Thursday, the south-western city was hit by flashes of violence, with police using tear gas and protesters partially burning the 300-year-old main door of Bordeaux city hall.

March 23 saw the biggest demonstrations so far against the reforms in towns and cities across France.

Police again clashed with demonstrators in the capital, charging at the crowds in the centre of the city.

Over the last week, there have been almost nightly protests after dark in France's cities with clashes between police and the groups known as "casseurs."

Translating to "breakers" in English, the anarchists are infamous for damaging bus shelters, starting fires, and smashing shop windows.

At least 450 people were arrested across the country on Thursday.

Hundreds of police officers were said to have been injured, as well as some protesters, including a woman who reportedly lost her thumb after being hit by a stun grenade fired by police.

The government says the changes are essential to make the country's pension system financially sustainable in the future.

But the unions say the pension reforms are unfair and unjustly impact women and lower-paid workers.

The government is determined to enact the legislation, which it hopes to bring in before the end of the year, but the opposition movement has vowed to continue to demonstrate until ministers scrap the reforms.