The fire was reported early Sunday afternoon. A large rescue operation was dispatched to the scene.
Residents in several stairwells were evacuated, and three people were taken to hospital, the police wrote on their website. None of them were seriously injured.
By 2:30 p.m., the fire was under control, Upsala Nya Tidning reported.
The cause of the fire is unknown. The police are filing a report of aggravated arson to investigate what happened.
