A woman and five children died in a fire Friday morning at an apartment in Ibaraki Prefecture and her 32-year-old husband later told police that he killed the six before setting fire to their home, investigative sources said.

Hirobumi Komatsu was arrested on suspicion of murder after he confessed to setting fire to the apartment where his 33-year-old wife and four children were found dead. A sixth victim, an 11-year-old girl, was confirmed dead after being taken to a hospital.

Komatsu allegedly killed the girl, who sustained stab wounds, at his home in a three-story apartment building in Hitachi city. He handed himself in to the police.

The six victims -- his wife, daughter and four sons -- were found in a room on the first floor of the building, the police said, adding the bodies of the five in addition to the girl also sustained wounds.

The police believe the boys were aged 7, 5, and 3-year-old twins.

According to a neighbor of Komatsu, his wife had asked him for a divorce.

The fire broke out at around 5 a.m. and was put out about an hour later after about 10 fire engines and ambulances rushed to the scene.

"My wife and five children were in my house," Komatsu, who also suffered burns, said, according to the police.

Komatsu is suspected of killing the girl at around 4:30 a.m. at home. When interviewed by police, he admitted to killing his daughter and implied that he had killed all five children and his wife, investigative sources said.

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A neighbor said Komatsu's wife and children moved into the apartment about three years ago and Komatsu later moved in and the family of five lived together.

The suspect had taken work off this week, saying his wife was sick, according to his workplace.

The apartment is in a nearly 40-year-old complex about 1.5 kilometers southwest of Ogitsu Station on the JR Joban Line.