A 32-year-old man was arrested Saturday for arson after a fire gutted the house where he lived in the central Japan prefecture of Nagano, apparently killing three of his family members, police said.
Three bodies believed to be those of the man's father, Hitoshi Nakamura, mother and grandmother in her 90s were found after the fire at the two-story house.
The man, whose identity was withheld by police, and his brother both escaped the fire without major injuries.
The fire broke out in the early hours of Saturday and was extinguished in about three hours.
The man has admitted to setting fire to his house, according to the police.