The incident occurred just before 8am on Friday morning in Midsommarkransen, a suburban district in Stockholm’s south west.
Emergency services arrived on the scene soon after to tackle the resulting blaze, however, the blast had already taken one person’s life.
“One person was found dead inside the apartment and one person was injured in the stairwell,” Jarmo Karlsten of the Stockholm emergency services told the Aftonbladet newspaper.
The injured person later died in hospital.
It was a neighbour who made the emergency call.
“There was an explosion heard, a crash or a bang, and then large amounts of smoke billowed out,” said Ulf Lindgren of the Stockholm police to the TT news agency.
Emergency services later confirmed the damages, stating that there were gas lines in the building, however, they could not confirm whether gas had caused the explosion.
“The fire is now extinguished and we’re investigating the building,” Karlsten told the paper.