(AFP) - France braced for more angry protests Wednesday after the killing of a teenager by police during a traffic stop that President Emmanuel Macron called "unforgivable".

The government said it would deploy 2,000 riot police to deal with any unrest, a day after a 17-year-old was shot in the chest by a police officer who then appeared to lie about the circumstances of the killing.

The shooting had already sparked unrest in several Paris suburbs overnight.

Celebrities and politicians expressed outrage and grief at the death of the teenager, with Macron calling it "inexplicable" and "unforgivable".

The teenager, named only as Nael M., was pulled over by two policemen on Tuesday for breaking traffic rules, prosecutors said.

Police initially reported that one officer shot at the teenager because he was driving his car at him, but this version of events was contradicted by a video circulating on social media and authenticated by AFP.

The footage shows the two policemen actually standing by the side of the stationary car, with one pointing a weapon at the driver. A voice is heard saying "You are going to get a bullet in the head."

The police officer then appears to fire point blank as the car abruptly drives off.

The car moved a few dozen metres before crashing. The driver died shortly after.

His death sparked immediate protests in Nanterre, a western Paris suburb.

Bins were set alight and a fire broke out at a music school, while police tried to disperse the protesters with tear gas.

Protests then broke out in some neighbouring suburbs.

Interior Minister Gerald Darmanin said Wednesday that 31 people had been arrested overnight, 24 police slightly injured and around 40 cars torched.

Darmanin added that 2,000 police would be deployed to deal with any further violence later Wednesday.

- 'Revolt for my son' -

Government spokesman Olivier Veran told reporters that Macron had expressed "emotion" at the shooting during Wednesday's weekly cabinet meeting, and called for "calm" on behalf of the government.

"A teenager was killed. That is inexplicable and unforgivable," Macron said during an official visit to Marseille, southern France.

"Nothing can justify the death of a young person."

The case had "moved the entire nation", he said, also expressing "respect and affection" for the family of the victim.

Prime Minister Elisabeth Borne tweeted she hoped that "our absolute demand for the truth will allow calm to prevail over anger".

The 38-year old policeman filmed firing the lethal shot was taken into custody and is under investigation for voluntary manslaughter.

Nael M.'s lawyer, Yassine Bouzrou, said he would file an additional legal complaint against the policeman for voluntary manslaughter, and also against his colleague for complicity in the shooting.

The lawyer also said that he would file a further complaint for false testimony against the policemen for claiming that Nael M. had tried to run them over.

There were two passengers in the car. One ran off and the other, also a teenager, was briefly detained.

Nael M.'s mother posted a video on the TikTok platform calling for a tribute march for her son on Thursday. "This is a revolt for my son," she said.

Celebrities also voiced disgust, concern and outrage at the shooting.

"I am hurting for my France," tweeted Kylian Mbappe, captain of the French men's national football team and star player at the Paris Saint-Germain club.

"An unacceptable situation. All my thoughts go to the friends and family of Nael, that little angel who left us far too soon," Mbappe said.

Actor Omar Sy, famous for his role in the film "The Intouchables" and the "Lupin" TV show, said on Twitter: "I hope that justice worthy of the name will honour the memory of this child."

- 'Police becoming like America's' -
Green party leader Marine Tondelier said that "what I see on this video is the execution by police of a 17-year-old kid, in France, in 2023, in broad daylight".

"I heard a policeman lie, his colleague lie, the prosecutor lie and the media lie", she said, adding: "You get the feeling that our police is becoming like America's."

Far-left politician Jean-Luc Melenchon said that "France no longer has the death penalty", and called for "a complete redesign of the police force".

Darmanin -- who has previously backed the police in similar situations -- called the video footage "extremely shocking" in parliament.

On Wednesday he said that the officer would be suspended "if the charges against him are maintained".

Paris police chief Laurent Nunez, meanwhile, described the shooter as a "seasoned police sergeant who had the trust of his superiors".

In 2022, a record 13 people were killed in France after refusing to stop for police traffic checks.

© Agence France-Presse