"The death toll thereby reached three people," a police source said.
Investigators said the explosion in an apartment block might have been caused by workers violating safety regulations when they were replacing gas pipes on Thursday.
Gas service employees claimed, however, that residents in the three apartments had not let them in Thursday.
Seven people were treated after the explosion. Two received serious burns and four people were taken to hospital to be treated for carbon monoxide poisoning or shock. One woman refused hospital treatment.
A police source said three apartments located one on the third, fourth and fifth floors had been destroyed completely. The apartment on the fourth floor was thought to have been the epicenter, but the source added though that experts were yet to verify the version.
Thirty people were evacuated from the block and accommodated in a recreation center. Psychologists and rescuers are working at the site.