The device had been placed in the letter box outside the property owned by the Metall union. It was discovered when someone went to collect the mail.
“Cables and possibly a battery were visible, so it was closed and the police were informed,” said Bjarne Andersson, duty commander at Värmland police, earlier in the day.
The building, which was mostly residential, was evacuated and police cordoned off the area. The bomb disposal unit arrived from Gothenburg at around 6pm.
After an inspection the technicians decided to destroy the device in the letter box itself.
“They blew up the object. We still don’t know what it contained – the bomb technicians took the pieces with them to Gothenburg for further technical investigation,” said Lars Bloom, Värmland police area manager, to TT.
It was still unclear on Thursday morning who was behind the incident, since no threats had been made in connection with the bomb.