Certain areas were sealed off to allow a total of 40 fire fighters access to a number of fires started in the area.
Police spokesman Lars Tunefjord said that reports of shooting “may have been bangs heard in connection with the fires.”
According to fire brigade workers, the gang set light to a café, a school and a building adjacent to n apartment block.
Around 60 residents of the apartment block on Paprikagatan had to be evacuated as a result of the the smoke emanating from the building next door.
Police estimate that the gang consisted of half a dozen members. There have as yet been no arrests in connection with the disturbances.
Police have not yet established a motive for the attacks.
Fire fighters have remained in the area in order to be able to act quickly in case of further outbreaks.