Photo/Illutration Police on Sept. 24 continue searching for clues into the stabbing deaths of a married couple at their house in Sakai, Ibaraki Prefecture. (Kazuyoshi Sako)

SAKAI, Ibaraki Prefecture--A couple were fatally stabbed and two of their children injured by a home intruder who attacked the family members while they slept, police said Sept. 23.

Mitsunori Kobayashi, 48, a company employee, and his wife, Miwa, 50, a part-time worker, were found bleeding on futon mats on the second floor of their secluded house in Sakai’s Wakabayashi district early that day, Ibaraki prefectural police said.

They had been stabbed in their faces and necks and were pronounced dead at the scene.

Miwa had made an emergency call around 12:40 a.m. on Sept. 23, saying, “Help us.”

The couple’s 13-year-old son was sleeping in a room on the second floor when he suffered slash wounds on both legs and one arm, police said.

Their 11-year-old daughter who was sleeping in the same room as her brother told police that she had pain in both hands.

“It felt like I was sprayed with something like tear gas,” an investigative source quoted her as saying.

The two children were taken to a hospital. Their injuries were not life-threatening.

The couple’s 21-year-old daughter, a college junior, was sleeping on the first floor and was not injured.

The house, which had some entrances that were not locked, showed no signs of having been ransacked by the intruder, police said. The weapon has not been found.

Officers in the murder investigation searched the surrounding area and found slippers outside the house.

On Sept. 24, police found stains that appeared to be blood on one of the slippers.

Police said they believe the intruder wore the slippers in the attack against the family members and then removed them after leaving the house.

The crime scene is located in a quiet area with farm fields and scattered residences near the border with Noda, Chiba Prefecture. The victims’ house is surrounded by trees and secluded from other homes.

The family moved to the house, which had been used by Miwa’s parents, more than 10 years ago, according to a neighbor in her 60s.

The neighbor said she frequently saw Mitsunori and his son playing catch on the road in front of their house.

She said Miwa was always polite when the neighbor shared vegetables with the family.

“They were a good family, and they gave no indication that they were in any trouble,” she said.