France’s Prime Minister Sébastien Lecornu has warned that any escalation in the country’s current wave of student protests would be “irresponsible”, following the arrests of 164 people on Monday.

The demonstrations, which started in Paris and have seen teenagers blockading their schools for days, stem from issues including overcrowded classes and teacher shortages.

Lecornu cited reported incidents at protests in a post on X, saying: “Fireworks, fires, violence near high schools: nothing justifies endangering students, staff, or police officers.”

But a French union that defends the interests of high school students said the protests were a “legitimate response” to the conditions they face.

Interior Minister Laurent Nuñez said 12 members of the security forces, 12 students and three school staff were injured on Monday, while 180 schools were affected.

He did not provide further details on those who had been arrested.

The movement at French lycées, equivalent to sixth form in the UK or high school in the US, began last week in the Île-de-France region around Paris.

Incidents of vandalism were reported, along with fireworks being aimed at police, and the protests have now spread to other regions in France.

According to the AFP news agency, four high schools were reportedly blockaded in the southern regions of Alpes-Maritimes and Var. Protests have also been reported in Marseille, the northern Lille area and Sedan in the north-eastern Ardennes.

The Union Syndicale Lycéenne, which represents students, defended the protests in a post on social media.

“Lack of teachers and staff, dilapidated schools, overcrowded schedules and classes, stress caused by Parcoursup [the web platform used in France for students to apply to the first year of higher education]… These issues are by no means inevitable, but simply the result of 10 years of Macron’s policies and the lack of resources in the national education system,” it said.

It called on students to blockade schools on Tuesday in defence of “their rights and against budget austerity”.

On the same day, unions representing teachers, hospital staff and civil servants also called for a day of walkouts to protest against issues including low wages and working conditions.

In response to the student movement, Lecornu said “the difficulties of high schools must be heard and addressed”, but that “violence must be condemned unequivocally, and its perpetrators must answer for their actions”.

The prime minister also accused the far-left France Unbowed (LFI) party of urging students to expand the movement.

Jean-Luc Mélenchon, LFI’s leader, blamed the Lecornu government for having “ordered the crackdown” on the protest, adding that the high school students taking part were “harmless”.

But Nuñez said the demonstrations and blockades were “not very typical protest movements”.

“It is much more like urban violence, with a number of individuals who were masked, equipped with fireworks in tubes, equipped with projectiles, who clearly wanted to confront the internal security forces,” he said.

“It wasn’t about making demands; it was really violence in its purest form.”

Since the protests began, several incidents involving violence between students and police officers have been reported.

In one incident, a police officer reportedly fired a round from a grenade launcher used for crowd control, injuring a high school student, according to France’s BFMTV.

Investigations have been launched into these incidents, the broadcaster added.