Police and an ambulance are on the scene after several people raised the alarm about an explosion at a residential building north of Märsta.
According to information to TV4 Nyheterna, it was a hand grenade that was thrown at the house. Residents of the house must have connections to criminal networks.
The police are currently hunting a suspected perpetrator, who according to witnesses has disappeared in a black car.
The national bomb disposal service must carry out a technical investigation at the site which has been cordoned off.
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