11 December 2018, Hessen, Kassel: Several hundred pupils demonstrate in the city centre of Kassel. The alliance "Struggle for Our Future" had called for a school strike to protest against the faltering refurbishment of dilapidated schools in Kassel. Photo: Uwe Zucchi/dpa

11 December 2018, Hessen, Kassel: During a demonstration in downtown Kassel, a schoolgirl holds up a poster with the slogan "All I want for Christmas is Bildung". The alliance "Struggle for our Future" had called for a school strike with several hundred participants to protest against the faltering renovation of dilapidated schools in Kassel. Photo: Uwe Zucchi/dpa

11 December 2018, Hessen, Kassel: During a demonstration in downtown Kassel, a schoolgirl holds up a poster with the slogan "Rich parents for all". The alliance "Struggle for our Future" had called for a school strike with several hundred participants to protest against the faltering renovation of dilapidated schools in Kassel. Photo: Uwe Zucchi/dpa

11 December 2018, Hessen, Kassel: During a demonstration in downtown Kassel, a schoolgirl holds up a poster with the slogan "More money for education". The alliance "Struggle for our Future" had called for a school strike with several hundred participants to protest against the faltering renovation of dilapidated schools in Kassel. Photo: Uwe Zucchi/dpa

11 December 2018, Hessen, Kassel: During a demonstration in Kassel's city centre, a schoolgirl holds up a poster with the word "future". The alliance "Struggle for our Future" had called for a school strike with several hundred participants to protest against the faltering renovation of dilapidated schools in Kassel. Photo: Uwe Zucchi/dpa

11 December 2018, Hessen, Kassel: Several hundred pupils demonstrate in the city centre of Kassel. The alliance "Struggle for Our Future" had called for a school strike to protest against the faltering refurbishment of dilapidated schools in Kassel. Photo: Uwe Zucchi/dpa

11 December 2018, Hessen, Kassel: During a demonstration in downtown Kassel, a pupil holds up a poster with the word "dissatisfied". The alliance "Struggle for our Future" had called for a school strike with several hundred participants to protest against the faltering renovation of dilapidated schools in Kassel. Photo: Uwe Zucchi/dpa

11 December 2018, Hessen, Kassel: Several hundred pupils demonstrate in the city centre of Kassel. The alliance "Struggle for Our Future" had called for a school strike to protest against the faltering refurbishment of dilapidated schools in Kassel. Photo: Uwe Zucchi/dpa