Rioters set fire to cars and a medical centre in the city on Tuesday night after news spread that an officer had shot dead the 22-year-old, named by local newspaper Ouest France as Bubakar, after stopping his car over an infraction.
Youths clashed with police in the northwestern neighbourhood of Breil where the killing took place, lobbing molotov cocktails, before the unrest spread to two other poorer districts with a history of gang violence.
Burned-out cars littered the streets on Wednesday morning.
Interior Minister Gerard Collomb condemned the violence, adding that “all the necessary resources are being mobilised” to “calm the situation and prevent any further incidents”.
Local police chief Jean-Christophe Bertrand said the youth had hit a policeman with his car, lightly injuring him, after a squad stopped the vehicle at around 8.30 pm for an alleged infraction and tried to take him to the police station for identification.
“One of his colleagues then fired, hitting the young man who unfortunately died,” Bertrand told reporters.
He was hit in the carotid artery and declared dead on arrival at hospital, police sources said.
Judicial police and a national watchdog which investigates claims of police wrongdoing are investigating to clarify “the facts and determine in what circumstances the policeman used his weapon,” said Pierre Sennes, public prosecutor for Nantes.
He said on Wednesday that the young man had been wanted by police in Creteil, near Paris, for robbery and other offences.
'I saw everything burning'
French police have a long history of strained relations with youths in poor, immigrant-heavy suburbs — not least since the death of two teenagers, electrocuted while hiding from officers, sparked nationwide riots in 2005.
The assault of a young black man by police — which led to officers being charged, including for rape after a truncheon was shoved up the youth's anus — sparked fresh unrest last year.
In January, the government vowed a crackdown on urban violence after shocking video footage emerged of a policewoman being beaten by a crowd of youths in the Paris suburbs on New Year's Eve.
Breil, the Nantes neighbourhood where the young man was shot dead Tuesday, is a socially mixed district home to a large housing estate with a history of
Police had boosted their presence in the area after a series of violent incidents on June 28.
Malakoff and Dervallieres, the other neighbourhoods hit by riots on Tuesday, have been plagued by drugs and poverty for years.
They fall into a category of problem neighbourhoods which are set to receive extra police help from next September under reforms by President Emmanuel Macron.
A wall damaged a car being driven by a man who was shot dead by a police officer in the Nantes neighbourhood of Breil. Photo: AFP
Steven, 24, who lives in Breil, told an AFP journalist that he had “heard explosions” and headed to investigate.
“I saw everything burning. There were fires in the bins, the cars. They were breaking everything. It lasted ages,” he said.
Neighbourhood residents were in shock on Wednesday morning at the young man's death.
“That guy, he always had a smile on his face,” a young man who gave his name as Chris told Ouest France.
“He was a sweet guy. We have lost a friend, a brother.”
He added: “I knew him well. He was from Paris but he'd lived here for a while, he had family here. For us, he was a kid from the neighbourhood.”
Nationally, French police have complained of coming under increasing strain in recent years, with a parliamentary report released Tuesday detailing high suicide rates within the force.