Shortly after 7 pm, the incident began where an injured man was found in central Skellefteå.
Several people had left the scene after the incident.
The police label it as attempted murder / manslaughter.
The injured man was taken to hospital for treatment.
The site was cordoned off and a crime scene investigation is to be conducted.
During the evening, several police patrols worked on the incident.
By 10 p.m., five people had been arrested.
The police are questioning witnesses, and the five arrested will be heard later in the evening.
Prosecutors are then expected to make a decision on any arrests.
The injury status of the injured person is not known.