French prosecutors said magistrates will investigate a police officer who shot and killed a 17-year-old driver for "voluntary homicide," following two days of violent fires and violent protests.

Overnight, protesters set cars and public buildings ablaze in Paris suburbs and unrest spread to some other French cities and towns, despite increased security efforts and the president's calls for calm.

The killing of 17-year-old Nahel during a traffic check Tuesday, captured on video, shocked the country and stirred up long-simmering tensions between young people and police in housing projects and other disadvantaged neighbourhoods around France.

Nanterre prosecutor Pascal Prache said that based on an initial investigation, he concluded that "the conditions for the legal use of the weapon were not met."

Two magistrates have been named to lead the investigation, he said. Under the French legal system, which differs from the US and British systems, magistrates often assigned to lead investigations.

Prache said he requested that the officer be held in custody. That decision is to be made by another magistrate.

Nahel's surname has not been released by authorities or by his family. In earlier statements, lawyers for the family spelled the name Nael.

Clashes first erupted Tuesday night in and around the Paris suburb of Nanterre, where Nahel was killed, and the government deployed 2,000 police to maintain order Wednesday. But violence resumed after dusk.

Police and firefighters struggled to contain protesters and extinguish numerous blazes through the night that damaged schools, police stations and town halls or other public buildings, according to a spokesperson for the national police.

The national police on Thursday reported fires or skirmishes in multiple cities overnight, from Toulouse in the south to Lille in the north, though the nexus of tensions was Nanterre and other Paris suburbs.

Police arrested 150 people around the country, more than half of them in the Paris region, the spokesperson said. She was not authorised to be publicly named according to police rules.

The number of injured was not immediately released.

French President Emmanuel Macron held an emergency security meeting Thursday about the violence.

"These acts are totally unjustifiable," Macron said at the beginning of the meeting, which aimed at securing hot spots and planning for the coming days "so full peace can return."

Macron also said it was time for "remembrance and respect" as Nahel's mother called for a silent march Thursday in his honor on the square where he was killed.

Multiple vehicles were set ablaze in Nanterre and protesters shot fireworks and threw stones at police, who fired repeated volleys of tear gas.

Flames shot out of three stories of a building, and a blaze was reported at an electrical plant. Fire damaged the town hall of the Paris suburb of L'Ile-Saint-Denis, not far from France's national stadium and the headquarters of the Paris 2024 Olympics.

The police officer accused of the killing is in custody on suspicion of manslaughter and could face preliminary charges as soon as Thursday, according to the Nanterre prosecutor's office.

French activists renewed calls to tackle what they see as systemic police abuse, particularly in neighbourhoods like the one where Nahel lived, where many residents struggle with poverty and racial or class discrimination.

Government officials condemned the killing and sought to distance themselves from the police officer's actions.

Macron called the killing "inexplicable and inexcusable" and called for calm. "Nothing justifies the death of a young person," he told reporters in Marseille on Wednesday.