The alarm about the explosion came at 10.30 pm on Tuesday evening after a loud bang was heard in Enskededalen in southern Stockholm.
Pictures from the scene show how an entrance door was damaged by an explosion and information to SVT claims that it was a hand grenade that detonated in a stairwell.
A man lives at the address who, according to SVT, is linked to gang crime.
He is said to have moved in the same circles as the man who was murdered in Rinkeby on Christmas Day.
National bomb protection
The National Bomb Squad has been called to the scene and police technicians will now carry out a technical investigation.
There is currently no information that anyone was injured in connection with the explosion.
The police are investigating the incident as public vandalism, but have not yet made any arrests.