"We don't know if anyone is left in the homes. The fire has spread to several apartments," says Anders Wennegren, duty officer with the police in Region West.
The alarm came in at 12:10 a.m. Wednesday night.
The police have opened a preliminary investigation into arson. A person in his 50s has been arrested on suspicion of the crime.
The fire is fully developed, and it is still unclear how many homes have been affected.
