"It's a chaotic incident, and there are a lot of people out there who have seen this," says police spokesman Leif Fransson.
The man was hit in the leg as he walked toward the police with the object raised. He suffered non-life-threatening injuries and was taken to hospital by ambulance.
According to Fransson, it is not yet clear what crimes the man will be suspected of.
Because the police fired live rounds, the incident will be investigated by the police's Special Investigations Department.
