"It is suspected to be a hand grenade," says the rescue service's duty officer, Patrick Johansson, to Eskilstuna-Kuriren.
A gate was damaged as a result of the incident and bomb disposal units worked at the scene overnight. No one was injured.
Two people were arrested during the night and taken into custody in the morning. One is suspected of causing public danger and the other is suspected of aiding and abetting the crime.
The alarm about the incident came in at 10:50 p.m.
