A 51-year-old woman was fatally stabbed Saturday afternoon by a group of young men who barged into her home in the town of Haguro, Yamagata Prefecture, local police said.
According to investigators, at least three men entered the home of civil servant Akira Sato, 52, in the afternoon and tied up his wife and 16-year-old daughter.
One of the men then stabbed the two women with a sharp knifelike object. Kayoko, his wife, was stabbed once in the left side of her chest and died from blood loss at a hospital in Tsuruoka. Atsuko, his oldest daughter, sustained minor injuries to her buttocks, police said.
An autopsy later showed that woman died after the weapon punctured her heart, police said.