Several families were evacuated from the row of terraced houses in the town of Hallsberg, near Örebro, but nobody else was injured.
“It is possible that they died of burns, but we don’t know yet. The post mortem examination will reveal the causes of death,” said Torbjörn Carlsson, spokesman for Örebro Police.
The fire broke out at around 4am in the apartment. The fire was contained in the apartment and the fire brigade believed it to be extinguished by 6am. However, later in the morning the fire started to burn fiercely again, spreading to the roof. Six apartments were said by the fire brigade to be threatened.
Police said they do not believe anyone else to have been in the apartment in which the girl and her father died.