The French government has vowed to bring an end to violence in the usually placid eastern city of Dijon after it was hit by a fourth night of unrest allegedly linked to score-settling by members of the Chechen community. According to police, the incidents appear to have been sparked by an alleged assault this month on a 16-year-old Chechen boy, prompting reprisal raids. Some reports suggested Chechens had travelled to Dijon from all over France as well as neighbouring Belgium and Germany. The unrest has focused on the low-income district of Grésilles, which has a large north African population. On Monday evening, dozens of hooded men carrying arms and crowbars had gathered in Grésilles, shooting in the air, destroying video surveillance cameras and setting fire to bins and vehicles, police said. Riot police took 90 minutes to put an end to the violence, leaving the area calm overnight. Four people were detained. The deputy interior minister, Laurent Nuñez, travelled to Dijon, vowing an “extremely strong response”, with more than 150 police and paramilitary gendarmes mobilised to halt any unrest on Tuesday evening. “I want to send a very clear message to the hooligans we have seen brandishing weapons, to the individuals who have come here to commit violence in Dijon,” he said. Police would remain at the scene “as long as they need to”, he added. The violence in a city better known for its mustard and gastronomical products has shocked France and prompted condemnation from across the political spectrum. “Seeing young people brandishing arms, 100 people fighting, being aggressive, it’s unacceptable,” the agriculture minister, Didier Guillaume, told the CNews TV channel. The far-right leader Marine Le Pen, a frequent critic of the government of Emmanuel Macron over public order issues, scheduled a press conference in Dijon later on Tuesday. The socialist mayor of Dijon, François Rebsamen, criticised what he saw as insufficient police deployment over the weekend. “As justice comes too late and the police do not have the means, the Chechen community decided to take the law into its own hands,” he told BFMTV. The regional prefect Bernard Schmeltz – the top local state official – defended the lack of forceful intervention by the security forces. The tactic of encirclement used “was the only practical strategy”, he said. “The local residents were not left abandoned,” he added in response to criticism of the security force’s apparent passivity. He said the incidents on Monday night had been due to local Dijon residents and not members of the Chechen community. The clashes came amid bitter criticism over alleged racism and brutality by French police, which has itself sparked protests in recent days.