Riot police used tear gas and water cannon in violent clashes with protesters during France’s largest school demonstrations so far.

The French interior ministry said at least 260,000 people took part in marches in multiple cities on Tuesday, including Paris, Marseille, Nantes ⁠and Lyon, while the inter-union group claimed as many as 450,000 demonstrators were involved across the country.

Half of France’s 3,700 high schools were shut or partially closed as a result of the protests, which started as an appeal for better conditions but have grown over the last fortnight and become increasingly dangerous.

A one year-old baby in a pram was hit by a firework in an incident near a school in Saint-Cyr-l’École, Paris, the day after a teenager lost a hand picking up a grenade thrown by police.

In Strasbourg, Lyon and Rennes, protesters set the streets ablaze as they torched barricades, and threw multiple projectiles and mortars towards the police. The government claims the protest movement has been hijacked by outsiders and morphed into urban violence.

French prime minister Prime Minister Sebastien Lecornu announced classes would be suspended for the rest of the week in a bid to calm the situation down.

“Burning down a high school does not improve the state of high school buildings,” he said. “Lynching a teacher does not help replace teachers.”

He also denounced the “extreme violence” that he said has been knocking “on the door of high schools”, which he “condemned unconditionally”.

Lecornu told lawmakers at least 215 teenagers and 85 school staff had so far been injured in the clashes to date, “the heaviest toll in decades paid by the school system”. His office said more than 700 police officers had also been hurt.

More than 6,000 people have been arrested over the last week, a figure set to increase as the result of Tuesday’s chaos. Authorities have been accused of using disproportionate force against young people.

Students, teachers and parents have all joined the protests to voice their anger over overcrowded classrooms, teacher shortages and dilapidated school buildings.

“There is such a gap between the elites and us,” said Hugo Vetzel, a recent high-school graduate in Strasbourg.

“We want more money for the national educational system so that high schools are renovated,” said Roberta, another recent high-school graduate at a protest outside Paris’ prestigious Henri IV school. Schools have been facing a ⁠list of problems from water leaks to rat infestations, she added.

In Paris, a woman wearing a white helmet held a placard reading “supportive parents” during a demonstration, which was also joined by MPs, including Ecologiste et Social’s MP Alexis Corbiere, and French director, screenwriter and actress Laetitia Dosch.

US president Donald Trump waded into the situation on Tuesday, blaming the protests on “Islam”, without any evidence and despite images and footage of the demonstrations showing otherwise.

“What’s happening in France is nothing less than out of control mass migration,” Trump wrote on his Truth Social platform. “This isn’t about schools, this is about Islam wanting to take over a once great Country!” he claimed.

The protests began in September in the deprived suburbs of Paris, before spreading nationwide, presenting a major challenge to President Emmanuel Macron’s cash-strapped government.

Macron, who was due to meet with ministers Tuesday evening to discuss the protests that have caused widespread disruption in the country’s education system.

The High School Students Union said more than half of France’s high schools ​were ⁠blockaded or would close for the day. Some local education authorities have tried to move classes online.

Lecornu has ordered his ministers to tackle the students’ leading demands. Those include ensuring absent teachers are replaced, reviewing the length of the 8 a.m. to 6 p.m. school day and the need for longer lunch breaks.

The government will also look at repairs needed to ageing school buildings, said Lecornu, who demanded ministers send in their first proposals by the end of October.

Six months before an election to replace Macron, his government and far-right leader Marine Le Pen’s National Rally party have accused the hard-left France Unbowed (LFI) and mayors of stoking the unrest. LFI denies the accusation.