Police responded immediately to reports of an explosion in Katrineholm. Officers confirmed no one suffered injuries during the incident. The blast shattered windows and damaged the building's facade.
Authorities arrested a teenage boy at the scene. Prosecutors now charge him with gross public destruction and serious violations of laws governing flammable and explosive goods.
According to the charges, the teenager detonated a hand grenate. He allegedly transported the explosive device between Eskilstuna and Katrineholm. Officials suspect someone ordered the boy to carry out the attack.
The teenager admits to the crimes. Katrineholm lies about 100 miles southwest of Stockholm in Södermanland County.
This case highlights ongoing concerns about youth involvement with explosives in Sweden. Hand grenade incidents have become more frequent in recent years despite strict weapons laws.