Swedish authorities moved eight injured to the hospital as fire engulfed a residential building in Norrköping city after a blast was reported on Sunday.
Amid rising flames, parts of the building collapsed.
Swedish police said that the building caught fire after an explosion took place in the stairwell of the building. Rescue workers have evacuated around 150 people from the site while eight people were slightly injured.
The fire could not be extinguished even after three hours as the rescue officials said that it would take around six more hours to control the fire which turned into big flames.
Police said that the building suffered extensive damage due to the explosion and the consequent fire as the authorities focus on saving lives and ensuring that no one has been injured.
The cause of the detonation was not known, and the National Bomb Squad was called to the scene.