French students have clashed with police in front of a high school near Paris, in what authorities have described as "intolerable" attacks.
The violence broke out on Monday morning in Compiègne (Oise), north of the French capital, after a police patrol had been alerted to rubbish bin fires.
Videos on social media showed a group of youths surrounding an abandoned police car outside the Lycee Mireille Grenet school and trying to overturn it.
Compiègne police commissioner Pierrick Boulet said that "between 50 and 80" people targeted a police vehicle before the situation was calmed.
Four people have been arrested, and the local police department said on Twitter that "significant and inadmissible material damage" had been caused.
One firefighter also suffered minor injuries to the forearm after being hit by mortar fire while trying to extinguish a burning rubbish bin. The individual was taken to a local hospital.
The Mayor of Compiègne Philippe Marini also condemned the clashes in an interview with French television.
"I offer my strong support to the forces of law and order and the fire brigade who intervened in this unacceptable context," Marini later said on Facebook.
"My thoughts are also with the teachers and students who deplore this violence."
The President of the Departmental Council of Oise tweeted that perpetrators of the violence should be "firmly punished without delay".
"It is intolerable that such violence can take place in France, especially around a high school," said Nadege Lefebvre.
The rectorate of Amiens has denied that the clashes were linked to protests against keeping French schools open during the COVID-19 pandemic, according to AFP.
The rectorate said that the incidents were a result of a "climate of external violence that impacts the activity of the establishment".
Monday's clashes came as urban violence separately broke out on Wednesday and Thursday in the area near Clos-des-Roses, where the police had also come under mortar fire.
Last week, riot police also pepper-sprayed students after they blockaded a Paris high school in protest over inadequate COVID-19 sanitary measures.
Teachers’ unions in France are due to hold a nationwide day of protests and strikes on Tuesday.