The suspect was arrested after he barricaded himself inside a building in a 12 hour standoff with police.
A 31-year-old man has been arrested in rural Japan after four people were killed in a rare gun and knife attack involving a 12-hour standoff with police.
The suspect was taken into custody on suspicion of murder after barricading himself in his father’s home near the city of Nakano, northwest of the capital Tokyo, at about 4.30am (19:30 GMT) on Friday.
The attack began on Thursday afternoon when a local man working on a farm saw a woman “running from the road shouting, ‘help me’,” he told national broadcaster NHK.
“Behind her was a man wearing camouflage and carrying a large knife, who stabbed her in the back,” the 72-year-old witness added.
The suspect is accused of shooting dead two police officers who arrived at the scene after the witness called emergency services.
The two officers, who were allegedly shot in their car, and the woman were taken to hospital where they were pronounced dead within hours.
Another elderly woman also died after an apparent attack. She had been lying on the ground outside the house since Thursday afternoon and police had been unable to get to her, media said.
The rampage in a rural area of the western region was a rare instance of violent crime in Japan, which has a low murder rate and some of the world’s toughest gun laws.
No motive has yet emerged in the killings, nor has the suspect been formally identified, although several local media reported that he is the son of the speaker of Nakano’s city assembly.
“We pray for the souls of the deceased and express our heartfelt condolences to the bereaved families,” top government spokesman Hirokazu Matsuno told reporters.
“Police are investigating to uncover the whole picture of the incident, including how the crime developed and its background.”
Few other details were known about the attack, including the suspect’s motive.
Nagano prefectural police are due to hold a press conference later on Friday.
Japan was left reeling in July last year when former Prime Minister Shinzo Abe was shot while he was campaigning,
Last month, a man was arrested for allegedly throwing a “smoke bomb” towards Prime Minister Fumio Kishida as he campaigned in the western city of Wakayama.
Kishida was unharmed and a man arrested at the scene will undergo a three-month psychiatric examination, a regional court said this week.