Protests flare near Paris after 17-year-old shot dead during police traffic stop

France was bracing for further unrest on Wednesday evening following the death of a 17-year-old boy who was allegedly shot by police during a traffic stop.

The incident triggered violent protests in several suburbs of Paris overnight on Tuesday, during which 24 police officers were injured and 40 cars were set alight, French authorities say.

An extra 2,000 police officers were mobilized Wednesday afternoon in anticipation of the violence stretching into a second evening.

The officer who allegedly shot the teenager was put in custody on Tuesday after the boy, identified as Naël, died after being pulled over at a traffic stop in the Parisian suburb town of Nanterre. The officer will remain in custody for another 24 hours to undergo questioning by prosecutors, Nanterre prosecutor's office told CNN.  

French President Emmanuel Macron described as "unjustifiable" the fatal shooting of the youth, who was in the car, a Mercedes AMG, with two others at the time of the incident, prosecutors said.

Speaking to journalists in Marseille, Macron said: "Nothing, nothing justifies the death of a young man."

"I would like to express the emotion of the entire nation at the death of young Naël, and give his family of our solidarity and the affection of the nation.

"We need calm for justice to carry out its work. And we need calm everywhere because the situation we can't allow the situation to worsen," Macron added.

The death of the 17-year-old was pronounced at 9:15 a.m. local time "following at least one gunshot wound" and despite the intervention of emergency medics, the Nanterre prosecutor's office said.

A passenger in the vehicle was taken into custody and later released, while another passenger, who is believed to have fled the scene, is missing, the statement said.

An autopsy and additional examinations, including a toxicology report, have been ordered by the prosecutor's office.

The incident is being investigated by national police, French Interior Minister Gerald Darmanin said on Twitter.

"Following the death of a young driver in Nanterre, who was being checked by two police officers, the IGPN has launched an investigation to shed light on the circumstances of this tragedy," he said.

Earlier, Paris Police Chief Laurent Nunez told CNN affiliate BFMTV in an interview that the officer fired when the teenager refused to follow police instructions.

"This vehicle made a first refusal to comply, then it was blocked in the flow of traffic where there was a new control attempt by the two police officers," he said. "At that time the driver, who had first turned off the engine, restarted the vehicle, then left. It was in this context that the policeman used his firearm."

Angered by the teenager's death, protesters took to the streets in Nanterre Tuesday. Images show firefighters extinguishing a burning car during the protests.

Around 350 police and paramilitary officers were mobilized, mostly in Nanterre, to quell the clashes, which continued through the early hours of Wednesday, Nunez told French broadcaster CNews on Wednesday.

He said 24 people were detained. "This mobilization will be prolonged for as long as necessary," the police chief said, as he called for "calm."

"We have to respect the principle of the presumption of innocence," he said.

Celebrities and some politicians voiced disgust, concern and outrage at the shooting.

"I am hurting for my France," tweeted French men's national football team captain Kylian Mbappe and star player at Paris Saint-Germain. "An unacceptable situation," he said.

Actor Omar Sy, star of 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."

CNN's Mylene Loubiere-Anderson and Teele Rebane contributed reporting.