The blast happened at 1am at the street Gyllenstiernsgatan in the Östermalm area of the Swedish capital, but could be heard several kilometres away. It damaged the building and parked cars, with broken glass and other debris covering the area.
“We believe that the explosion happened in or at the building, but exactly where is still unclear. There are damaged cars nearby, but the explosion probably didn’t happen in them,” Stockholm police spokesperson Mats Eriksson told the TT news agency early on Monday.
TT photographer Anders Wiklund was at the scene on Monday morning and described the blast as “an extremely powerful explosion that was heard across all of Stockholm”.