Police received their first alerts about the explosion in the stairwell of an apartment building at around 2am on Sunday morning.
“If it was aimed at someone who lives in that stairwell, it might have been meant to send a message or a signal,” Fredrik Bratt told the TT newswire. “If your intention is to really hurt someone, you don’t do it with this kind of action.”
The blast damaged several doors, but left no one injured and no residents have had to be evacuated.
“If anyone had been coming out into the stairwell during the detonation, then there would have been a risk of injury,” Bratt said.
Police have interviewed all residents in the building, but have yet to arrest a suspect in the case.
Bratt said the officers investigating the case would now examine the lives of the building's residents to try to understand if anyone had reason to threaten them.
“There are many points of interest. The investigation should show what happened,” he said.