An explosion occurred in the Hjortmossen area in Trollhättan on Sunday evening.
Several alarms about loud bangs were received at 23.15 and when patrols arrived at the scene, material damage was discovered at a rental property.
There is damage to a door and broken windows, but it's not extensive damage and there are no personal injuries, says Johan Josarp, duty officer at Police Region West.
The national bomb squad was called to the scene and at 3 am, the police technicians could begin their work.
It is still unknown what caused the explosion.
No one is currently detained, says Johan Josarp.
The incident is being investigated as general reckless destruction.