A powerful explosion in an apartment building in the Swedish city of Gothenburg has injured at least 16 people, and police are investigating whether an explosive device was placed at the scene.
The blast occurred just before 5am and fire spread to several apartments.
Fire fighters pulled people from the building while other residents used tied sheets to lower themselves from balconies as grey smoke billowed out of stairwells and windows.
"The whole apartment vibrated, the bed vibrated," Lars Hulten told the Göteborg Tidning newspaper.
People "hung from balconies — there was one who fell", he added.
Hundreds were forced to evacuate.
"It's obvious that a crime cannot be excluded," Interior Minister Mikael Damberg told a news conference.
Thomas Fuxborg, a spokesman for the Swedish police, said it appeared the explosion was "not of natural causes" and a preliminary investigation was underway.
A gas leak was ruled out by emergency services.
"We suspect someone could have placed something that has exploded," Mr Fuxborg told a news conference, adding the fire was not under control.
"We have one, maybe two places with fire in this building and the rescue services are working hard to limit it and get it under control."
Swedish media said investigators were considering several theories, including gang related violence.
Sweden has been plagued by soaring gang crime in recent years, with rival groups using explosives and firearms to settle scores
Prime Minister Stefan Lofven said it was too early to say exactly what had happened in Gothenburg, but the whole of Swedish society would respond if criminals were behind the explosion.