There are no reports of anyone being injured. Witnesses are said to have seen people running from the scene in connection with the explosion, according to the police.
To ensure that there is nothing undetonated at the site, we have called in the National Bomb Protection, says the police's press spokesperson Magnus Jansson Klarin.
The incident is being investigated as general endangerment and a crime against the law on flammable and explosive goods.
No one has been arrested in connection with the incident.