The police were alerted shortly before 01:00.
The man is said to have been knocked over completely unprovoked and beaten so that he started bleeding. At the moment, the police have no suspects in the assault.
About half an hour later, another man in his 30s contacted a police patrol in Grängesberg and told them that he had also been beaten by an unknown perpetrator during the night.
It is unclear if there is a connection between the two events.