A 15-year-old youth died on Saturday after he was shot during a night of gangland violence in Poitiers, western France.
The teenager, who has not been named, was hit in the head on Thursday night during a shootout linked to control for drug trafficking networks.
Four other youths aged 15 and 16, who were also shot in mass brawls involving up to 600 people in the city's Les Couronneries district, were recovering from their injuries in hospital on Saturday.
"It started off with a shooting at a restaurant and it ended up with a clash between rival gangs which involved several hundred people," French Interior Minister Bruno Retailleau told BFM TV.
Retailleau dispatched hundreds of extra police to the city on Friday after the violence.
He has vowed tougher action as part of an effort to undermine the rise of Marine Le Pen's National Rally party.
Fears
Concerns over delinquency and insecurity have been cited as reasons behind voters choosing Le Pen's group which says it will do more than other parties to tackle crime.
Jean-Marie Girier, the top police commander for the Vienne region where Poitiers is located prefect, described the Les Couronneries quarter as the home of several major drug-dealing spots.
"What happens there means that police have to go in on a daily basis but it it remains relatively calm,” he said. “It's not run by drug dealers, even if there can be tensions."
On 26 October in Rennes, a five-year-old was hit by bullets in a spat between drugs gangs and is still in hospital.
"These shootings aren't happening in South America, they're happening here in France," Retailleau told the French broadcaster RMC.
“We are at a tipping point and the choice we have today is between a general mobilisation against this kind of thing or the Mexicanisation of the country."