Senior Superintendent Carlito Dimaano, provincial police director, identified the victims as Librada Carasig, 70, her children Lolita Mautil, 50, Nilda, 40, and Reynaldo, 36, and five-year-old grandson Raymond Carasig, Reynaldos son.
Dimaano said the victims were sound asleep in their house along Durian street in Barangay San Isidro when the fire broke out at about 12:31 a.m.
Investigation showed that an unattended lighted candle caused the blaze. Arson probers said the Carasigs usually put off the lights and just lit a candle when sleeping.
The one-hour fire also gutted three other houses belonging to the victims relatives.
An arson prober said the victims were found huddled in one corner of their burnt house.