PARIS (AP) — The French government sent police reinforcements and a top official to the Dijon region Tuesday to quell four nights of unusually violent clashes between rival groups that have left several injured and cars burned and rattled the community.

The exact reasons for the unrest are under investigation, but local officials say it appears linked to the drug trade and tensions between members of France’s Chechen community and other groups.

Similar clashes erupted in the Mediterranean city of Nice in recent days, which the mayor attributed to tensions over drug territory between local Chechen residents and their rivals. Four people were reported injured there.

The unrest in Dijon’s Gresilles neighborhood began last week after a 16-year-old from France’s Chechen community was attacked by local residents, according to the regional prosecutor.

Members of the Chechen community called for revenge on social networks, and a group of 50 descended on the area Friday, according to a local police official. A pizzeria manager was seriously wounded by gunfire, and the next day some 200 people turned out, the official said.

After tensions continued through the weekend, the interior minister ordered police reinforcements to the area and announced Monday that the government would take over management of the situation.

Images from BFM television showed two cars and several garbage cans on fire Monday, black smoke rising over a leafy neighborhood of low-rise apartment buildings. Young people wearing hoods and masks carried metal bars or bats as they roamed the area, and a makeshift gasoline bomb in a plastic bottle lay on the pavement.

A police helicopter circled overhead, and a dozen police vans lined a nearby street as firefighters sought to douse the scattered blazes. People looking out from nearby balconies covered their mouths from the smoke.

The local administration says at least 10 people have been injured so far.

As of Monday, no one had been arrested.

Unidentified local residents told BFM they felt abandoned by police over the weekend.

“The Chechen community came to make people respect its own laws,” Mayor François Rebsamen said. “There weren't enough police" to take on such a large, well-armed group, he said.

After the government sent reinforcements, Nunez visited the area to show support for the population and insisted that “no one should carry out justice themselves.”

“At a time when we ... talk of violent police, racist police, the (officers) proved they are the guarantors of our republican order,” he said. He said the national reinforcements would remain in the area “as much time as necessary.”

Graffiti on a nearby shopfront read “Long Live Putin,” in reference to Russian President Vladimir Putin, whose military fought Chechen militants in two wars in the 1990s and early 2000s. France offered asylum to many Chechens at the time, and there are now Chechen communities scattered around France.

The unrest comes amid tensions between French police and the government. Amid protests around France over racial injustice and police brutality, the government said last week it would ban police from using chokeholds to subdue people. But the government backed down Monday after police themselves protested. France is experimenting with expanding the use of stun guns as a potential alternative.

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Nicolas Vaux-Montagny in Lyon contributed.