Several shells have been found at the scene, according to the police, but there is no information that anyone has been injured.
The police do not want to comment on whether there has been any potential threat against people at the address.
We still do not have any motive for why this has occurred at the scene, says the police's press spokesperson Daniel Wikdahl.
The alarm about the incident came in just after 04.00 in the night towards Tuesday, when people called the police because they had heard bangs.
The police have initiated a preliminary investigation into serious weapons offenses. The area is cordoned off for a technical investigation. So far, no one has been arrested.