A healthcare helicopter was shot at with a green laser at 17:00 on Monday, according to the police.
The helicopter was in Tierp municipality when the crew raised the alarm.
Green laser is special, it's very strong and goes very far. If you're hit in the eye, you can get very serious injuries, says the police's press spokesperson Pelle Vamstad.
No one was injured. The police have no information about whether there was a patient on board the helicopter at the time.
The incident is being investigated as aviation sabotage, a crime against the radiation protection law, and attempted assault.
The reason we're investigating a crime against the radiation protection law is that you need a permit to possess a green laser, says Vamstad.
No one has been arrested.