Late on Tuesday evening, the police were alerted to an apartment building on Mjölkvägen on Ersboda in Umeå. That after they received an alarm that several people had set fire to a staircase.

On Wednesday, a woman was arrested on suspicion of attempted arson, after questioning she was released but the suspicions against her remain.

The police are interested in getting in touch with people who may have made any observations in connection with the fire.