More than 250,000 people took to streets across France on Tuesday as teachers, parents, and union activists joined students who have spent the past two weeks protesting, what they say is, a poorly-funded high school system.

French police fired tear gas in Paris and Marseille, and used water cannons in Rennes, as tensions escalated. Footage showed clashes between the authorities and protesters. Some demonstrators lit fires in the streets and hurled projectiles. Other protests appeared more calm, with students holding signs calling out school issues such as staff shortages and overcrowded classrooms.

The scenes unfolded after Union Syndicale Lycéenne (USL) and Union Étudiante (UE) called for the blockade of high schools and universities nationwide. The groups urged “all trade union and political organizations to support our mobilization which extends beyond the walls of our institutions.”

Prime Minister Sébastien Lecornu told parliament that the protests amounted to “the heaviest toll in decades paid by the school system.” He said at least 215 teenagers and 85 educational staff had been injured in clashes. More than 700 police officers had incurred injuries.

France's Interior Ministry said around ​6,100 people had been arrested since the protests began roughly two weeks ago.

“Burning down a high school does not improve the state of high school buildings,” said Lecornu, referring to the reported violence as “unacceptable.”

Joanna, a university student who attended high school in a Parisian suburb, told the BBC that the police response has been “really aggressive.” She said high school pupils have been throwing objects on fire, but insisted "if they don't do that, they are not heard.” TIME has reached out to the Interior Ministry for comment.

A 15-year-old’s hand was blown off during an altercation between high school students and riot police in Northern France on Monday, according to François-Xavier Lauch, the prefect of Pas-de-Calais. La Voix du Nord, a regional newspaper, said the teenager had lost his hand and part of his lower arm after picking up a police grenade intended to be non-lethal. The General Inspectorate of the National Police (IGPN) is looking into the incident.

The Education Ministry reported the closure of at least 900 high schools on Tuesday as protests spread across the nation. The USL gave a much higher figure, saying that around 2,000 high schools had shut down.

Facing mounting pressure to get the protests under control, the French Education Ministry launched a national consultation for students on Monday. Open until Oct. 23, the portal is intended to provide a safe space for young people to express their concerns regarding France’s lycée system, the final three years of high school education. 

“It is essential for us to hear from all high school students and to take into account the diversity of their educational experiences,” said Education Minister Édouard Geffray. 

As the momentum behind the protest movement shows little sign of waning, you can see the scale of the widespread demonstrations in the images below.