Neighbours reported to police early on Sunday morning that a large explosion had rocked the area around Surbrunnsgatan 4 in central Stockholm. Twenty windows were blown out as result of the blast.
According to Eva Nilsson at Stockholm police something exploded under a parked car.
"To the naked eye the car is in principle intact."
A large area was cordoned off by police after the explosion, and Surbrunnsgatan was closed off between Birger Jarlsgatan and Valhallavägen.
Neighbour Ann-Charlotte Egmar says she was woken up by a large explosion around 7am.
"I ran to the window to see what had happened and saw a white cloud on the street. I was scared and wondered if anyone had been hurt. We rushed downstairs to see."
"Police wondered if the device had maybe not fully detonated."
Egmar has now been evacuated to her son.
"Residents that have gone out will not be able to return home until bomb technicians have analyzed the events in detail," said Eva Nilsson.