French students blockaded high schools and clashed with police across the country on Tuesday as public sector workers joined a national strike against the government’s planned budget cuts.

Police detained more than 400 people on Tuesday, many of them minors, and 48 law enforcement officers were injured, authorities told Al Jazeera. The Education Ministry said more than 330 high schools, just under one in 10, were affected by protests.

The movement began in the Paris region last week over overcrowded classrooms, teacher shortages, long timetables and overheated classrooms after the recent heatwaves, before spreading to Lille, Nantes, Rennes, Bordeaux, Marseille and Lyon. Masked pupils set fire to rubbish bins and threw bottles and paving stones at police, who responded with tear gas, according to AFP. In the Paris suburbs, teachers formed a line around protesting students to protect them from police.

Unions said some 300,000 people took part nationwide in the one-day action, while police estimated a turnout of 30,000 in Paris. The Guardian reported that an estimated 40% of primary school teachers stopped work, though the Education Ministry put participation among teachers and school staff at 11% and at below one in 10 among other civil servants. Professional firefighters joined marches, saying this summer’s wildfires exposed resource gaps, and civil aviation authorities warned of flight disruption.

CGT union leader Sophie Binet gave the government 48 hours to withdraw the planned cuts, denouncing what she called a fourth consecutive annual freeze in state employees’ base pay, part of a 2-billion-euro ($2.2 billion) savings push and a wider 54-billion-euro ($61 billion) austerity drive; the Guardian reported the planned cuts at 54 million euros. “The anger is immense. I warn the government, it must address the demands and revise the draft budget, which is dangerous for the country and is driving us straight into the wall of recession at 200 kilometres an hour,” Binet told BFM TV.

Prime Minister Sebastien Lecornu said escalating the school demonstrations would be “irresponsible” and wrote on X: “Fireworks, fires, violence near high schools: nothing justifies endangering students staff or police.” Jean-Luc Melenchon, leader of the hard-left France Unbowed party, responded: “The Lecornu government has ordered a crackdown. This brutality is irresponsible and has a clear racist undertone. Hands off our youth.”

Lecornu called Melenchon’s intervention an “irresponsible escalation” and said the racism accusation was “an insult.” “The duty of an elected official of the republic is to protect young people and call for calm. Exploiting their anger for partisan purposes is wrong,” he wrote.

Ryad Rani, president of the USL high school students’ union, said protesters were facing “a general lack of resources, overcrowded classrooms of sometimes 32-35 students and the shortage of teachers and staff.” He called a circular from the interior and education ministries directing police to keep order with a proportionate use of force “automatic and institutionalised repression,” adding: “They see the same reality as we do, and they’re angry,” as Caroline Cheve, secretary general of the FSU teachers’ union, said of the pupils.

Interior Minister Laurent Nunez said 164 arrests took place on Monday and 180 schools were affected that day, adding: “We cannot tolerate excesses.” Tuesday’s action across France came seven months before the presidential election, with opinion polls reflecting deep dissatisfaction with President Emmanuel Macron and his government.

The government is due to unveil its draft 2027 budget on Thursday.