The police are on the scene and have cordoned off the area.
There are no reports of personal injuries and the police do not yet have a clear picture of any material damage.
The National Bomb Squad is called to the scene.
Twice in 24 hours
It is the second time in a day that there has been an explosion in that particular area. Yesterday there was an explosion near Värnhemstorget. Then both buildings and vehicles were damaged. Four people have been arrested on suspicion of involvement in that explosion.
It is too early to say anything about a possible connection.
– We will of course look at it, but it is not something we can see right away, says Mikael Lindh.
The text is updated