The alarm came shortly after 1 a.m. on Monday. Photos from the scene show how a door has come loose and windows in the property have been smashed.
– We work on site together with the emergency services and ambulance. The property has been damaged, says Angelica Forsberg, police spokesperson to news agency TT.
Explosions in Norrköping
No one should have been physically harmed.
The residents have been housed and asked to stay in their homes and the National Bomb Squad has been called to the scene.