Three people – including two police officers – have been killed in an attack in central Japan, police said.
A suspect with a rifle and knife was holed up inside a building, police and media reports added.
A woman fell while being chased by the suspect, who then stabbed her with a knife and shot at two police officers as they arrived at the scene in a patrol car in Nakano city in Nagano prefecture, a witness told NHS public television.
The witness said he asked the suspect why he attacked the woman – and was told he wanted to kill her, NHK said.
The three victims were taken to a nearby hospital, where the woman was later declared dead, police said.
The two officers also died, NHK reported.
A fourth person who was hurt could not be rescued because he was near the suspect, the Kyodo News agency said.
Video on NHK showed police wearing bulletproof vests and carrying shields, with an ambulance nearby.
The area is in a quiet farming neighbourhood.
Police described the suspect as a man wearing a camouflage outfit, a hat and mask and sunglasses, Kyodo News said.
City officials urged those in the area to stay at home.
No other details, including about the suspect and the motive, were immediately known.
Violent crimes are rare in Japan.
It has strict gun control laws and only a handful of gun-related crimes annually.
But in recent years there have been some high-profile cases, involving random knifings on subways and arson attacks, and there is growing concern about homemade guns and explosives.
