The detonation occurred sometime after 2 am. The police have launched a hunt for the perpetrators, but by Friday morning, no one had been arrested.
No personal injuries have been reported.
I can't go into more than that we have launched a hunt for the perpetrator or perpetrators and they are suspected of general endangerment and crimes against the law on fire hazardous and explosive goods, says Mats Eriksson, press spokesperson at the Stockholm police.
A lot of glass in the stairwell
The explosion occurred on the sixth floor of the apartment building, but it is still unclear what exploded.
We don't think it's a hand grenade, but it's unclear for now. No one has been injured, but there has been some property damage, mainly some glass in the stairwell, so we have asked people not to leave their apartments because of it, says Mats Eriksson.
At least one apartment door has been damaged in the explosion.
There is also vandalism on the door, presumably to gain access to the stairwell.
Investigating potential target
A large area was cordoned off around the site, and the police are now trying to determine who or what the explosion may have been intended for.
We're looking at what's behind this and we're trying to determine a potential target. But we'll see what connections there are to serious crime, says Mats Eriksson.
There is no danger to the residents of the house or in the area.
Justice Minister Gunnar Strömmer (The Moderate Party) commented on the explosion during a press conference on Friday.
It's another brutal reminder that we're dealing with a criminality that has a vast criminal capital and is willing to use it in a way that can have serious consequences for completely innocent people.
