“Objects were also thrown at busses and trams; among other things a windshield was broken,” said deputy police commander Sven Persson.

Rocks were also thrown at emergency response workers. On the way to a fire in the neighbourhood of Gällbo, a firetruck was hit by a large rock that broke the windshield. Two firemen were injured.

“One guy had glass splinters in his eye and another had an injured arm,” Bo Holmlund of the greater Gothenburg Fire and Rescue Service (Räddningstjänsten Storgöteborg) told TT news agency.

The firemen were treated on the scene by paramedics and were then taken to the hospital, but neither of them were seriously injured.

Two cars caught fire on Friday night in the neighbourhood of Västra Frölunda in Gothenburg. Police said that when they arrived a lot of people were out on the street to see what had happened.

“The fire had evidently started in one car and then spread to the other,” Persson said.