The man has been taken to hospital. The condition of the injury is not known.
– From what I understand, we were able to talk to him before he was taken to hospital, says Mariana Persson, officer on duty at the police.
The police do not want to say what kind of cover was used. The alarm about the incident came at 3.30pm on Saturday.
The crime scene, which is outdoors, has been cordoned off for a technical investigation. The police are now looking for witnesses to the incident.
No suspect has been arrested.