French lawyers and rights groups have said that several teenagers have suffered war-like injuries from police weapons used during school protests, and an unprecedented number of children have been held in police custody, some of whom reported being hit or racially insulted.

France is in the fourth week of its biggest youth protest movement in decades, during which hundreds of high schools across the country have been blockaded as students demand the replacement of absent teachers and repairs to decrepit buildings.

Police have opened internal investigations into 36 allegations of officer violence against demonstrators, including four children allegedly being “mutilated” by explosive weapons, and six sustaining “significant injuries”, as well as other complaints over physical blows, insults or alleged sexual assault, the interior minister, Laurent Nuñez, told the senate.