PARIS (AFP) - Thousands of protesters took to the streets in France on Saturday (Dec 12) for a third consecutive weekend of demonstrations over a controversial security Bill that would limit filming of the police.

The authorities were girding for further possible violence after the last two such protests in Paris ended in rioting.

In the capital, several thousand protesters flanked on all sides by a huge deployment of riot police marched through the east of the city.

"Global repression, total regression," read a placard held aloft by one demonstrator, a reference to the new "global security" Bill which bans the "malevolent" publication of images showing the faces of police officers in action.

Tensions mounted as night fell, with police using water cannon to repel small groups of black-clad protesters who threw bottles and other projectiles at the security forces.

Interior Minister Gerald Darmanin tweeted that 81 people had been arrested in Paris by mid-afternoon and said the police had to deal with some "ultra-violent individuals".

Demonstrations were also held in Montpellier, Lyon and Lille.

Critics argue that the security Bill, which has been adopted by the lower house of parliament, will make it harder for journalists and citizens to document cases of police brutality.

Footage of white police beating up an unarmed black music producer in his Paris studio on Nov 21 amplified anger over the legislation, widely seen as signalling a rightward lurch by President Emmanuel Macron.

Other incidents caught on camera have shown police in Paris using violence to tear down a migrant camp.

In the face of mounting protests, Macron's ruling LREM party announced it would rewrite the Bill's controversial Article 24, dealing with filming the police.

But the announcement fell short of the mark for left-wing protesters and rights groups, who are demanding that the law be completely withdrawn.

In scenes reminiscent of the "yellow vest" anti-government protests of late 2018 and early 2019, shop windows were smashed and vehicles set alight last week in Paris as small groups of demonstrators clashed with police.

'Blurry cop'

On Saturday, the police said they had arrested several anarchist "black bloc" demonstrators in the middle of the crowd to try to prevent them from taking over the rally.

Demonstrating in Montpellier, 49-year-old doctor Anne-Marie Briand said she considered her "duty as a citizen is to ensure respect for our rights".

Briand carried a banner reading "a blurry cop is a dodgy cop" - a reference to the security law's requirement for the faces of on-duty police to be blurred in pictures and videos.

The recurring allegations of police brutality have become a major headache for Macron.

In a letter to a police union leader on Monday, he announced plans for a summit in January on how to improve relations between the police and communities.

"There is urgent need to act," Macron said in the letter to the Unite-SGP-FO police union, adding that the summit would also address the police's longstanding complaints over working conditions.