Concerns have also been stoked by the case of a 14-year-old hit in the face with a tear gas grenade last week. The boy’s lawyer said he had lost several teeth and suffered a fractured jaw in the incident at Saint-Ouen-l’Aumône, north-west of Paris, and a police officer has been charged.

And in a separate development on Wednesday, a 16-year-old suffered a serious hand injury outside a school in Strasbourg, reportedly while handling a mortar firework.

Prosecutors also said an investigation for attempted murder had been opened after a 17-year-old student protester complained an officer “held his head underwater” while trying to arrest him near a river in the north-eastern city of Belfort. French reports say the boy has himself been charged with aggravated assault for allegedly attacking the officer.

Addressing France’s National Assembly on Wednesday, both Nuñez and Education Minister Geffray said the speed at which the protests had turned violent was unprecedented.

Geffray said dozens of headteachers and deputies had been injured, many deliberately so, and alleged the movement had been “very quickly infiltrated by ultra-violent groups”.

“We have never seen anything like this,” he said of the disorder which officials report has harmed more than 200 students and 700 police officers, and prompted more than 6,500 arrests.

Nuñez later said he found it “excessive to speak of police repression of the movement”, insisting that officers were only acting in response to violence and damage.