Also in Köping, the police had to pull out early Monday night when residents were disturbed by young people who fired fireworks.
Early on Tuesday morning, it was time again - then an automatic alarm went off at Emausskolan in Västerås.
It turned out that someone had fired fireworks at the school and several windows had been damaged.
A report of damage has been made, there are currently no suspects.
Hear the police tell more about the events when, among other things, fireworks were fired at a police bus.