According to the police, something detonated at a stairwell and several people heard the bang and sounded the alarm.
- We only know that something has slammed in connection with a staircase.
There should be smoke in the stairwell but nothing burning.
Some windows must be broken, says Evelina Olsson at the police command center.
The police have cordoned off the site to be investigated by technicians and the national bomb squad will also go to the site.
- But there are no injuries, says Evelina Olsson.