Three siblings were found dead in the aftermath of an apartment fire that broke out Tuesday morning in Obihiro, Hokkaido, police and firefighters said.
The bodies were found in the same crib inside the first-floor apartment in the two-story building.
The children's father, Yasuyuki Chiba, a 22-year-old construction worker, 24-year-old mother, Kiyoko, 2-year-old brother and 1-year-old sister sustained light injuries in the fire, which broke out at around 8 a.m., they said.
The deceased victims are believed to be Rui, 4, Ryo, 3, and 6-month-old Momoka.
Police and firefighters believe the parents were unable to save the children because they were sleeping in a different room, where a kerosene stove was placed.
The cause of the fire is under investigation, they said.