The police in Västerås were alerted during the afternoon to the residential area Eriksborg where several people heard gunfire.
Several patrols are on site to investigate the incident, which is being investigated as attempted murder and serious weapons offense.
A larger area has been cordoned off, but there is currently no information about injuries and no one is in custody, says police press spokesperson Maria Hall.
The police are working, among other things, with door-to-door questioning and witness interviews.
