Apartment block blast in Sweden injures about 20

A powerful explosion in an apartment building in the Swedish city of Gothenburg injured up to 20 people on Tuesday, three of them seriously, and forced the evacuation of hundreds more.

Police have opened a preliminary investigation and say they suspect someone might have placed something that exploded. Fires spread to several apartments, and crews from the local fire department were still working to extinguish the flames. The cause of the explosion is unknown.