A hundred extra police have been sent to the northern French town of Amiens, 24 hours after a night of violence during which officers came under attack and a primary school was torched.
Tensions were still running high on Tuesday, with locals booing the arrival of Interior Minister Manuel Valls.
Problems began on Sunday night when police carried out spot checks on youths close to a funeral ceremony for two road accident victims. The following night the riots broke out.
Valls insisted: “Law and order must be established. Shooting an officer, burning a school, damaging infrastructure, is intolerable.”
But locals accuse the police of provocation. One woman complained: “The Minister said hurting policemen is intolerable. The night before they were injured we had several young people injured.
“We had gathered to grieve. The police came to tear-gas us, to shoot at us with flash-balls. We told them there are women and kids, but they replied: ‘We’re going to bury you all’.”
This is the first major law and order test for Francois Hollande since he was elected president in May. Incidents involving police have often been the spark for unrest in troubled neighbourhoods in recent years.