Protests that began in the Paris region over teacher shortages and packed classes have spread across France, leaving hundreds of students and staff injured and about 2,000 people detained.

French high school students say they are tired of overcrowded classrooms, too few teachers and poor learning conditions.

One of them, 15-year-old Kesia, told Reuters that her class has 35 students and not enough chairs. She said the lunch break is also too short for everyone to get food.

Their protest started in the Paris region last week and has since reached other parts of the country. Students have blocked school gates, set fires and clashed with security forces.

In Paris, fires damaged the entrances of two schools, and police fired tear gas at protesters. Similar scenes, including fires and fireworks aimed at police, were reported in Strasbourg, Marseille and Rennes.

As a result, about 400 of France’s roughly 3,700 high schools have closed, and some have moved classes online.

The injury toll is high. Education Minister Édouard Geffray says at least 170 students and 65 education workers have been hurt, including 40 school principals. More than 100 schools have been badly damaged.

Justice Minister Gérald Darmanin says about 2,000 people have been detained, most of them children.

Geffray blames violent groups for hijacking what began as a student movement. He also said the aim now is to get young people off the streets, “because they are in danger,” and he asked parents to keep their children away from the blockades.

The government says it will hold fresh talks with teachers’ unions, student organisations and parents’ representatives to deal with the students’ complaints.

The crisis comes at a bad time for President Emmanuel Macron, whose government is already under pressure over its budget plans.