The suspect was arrested outside the farm property near Nakano City in the Nagano region, with police confirming a fourth fatality overnight – an elderly woman who was found injured at the scene and later pronounced dead.

Japanese police have arrested a suspect in a rare shooting and stabbing incident that left four people dead, including two police officers, in Nakano City in the country’s central prefecture of Nagano.

Police have named the suspect as Masanori Aoki, the son of a local politician. The 31-year-old man, who had been holed up inside his father’s house after the attack, was arrested outside the farm property near Nakano.

In Thursday’s incident, police received a call with reports that a man had chased and then stabbed a woman. When officers rushed to the scene, the suspect fired something resembling a hunting rifle, striking four people, before barricading himself inside a building.

Among the casualties is a woman in her 40s, who was taken to hospital where she subsequently died. Two police officers, ages 46 and 61, who responded to the emergency, also died from their injuries, Japanese public broadcaster NHK reported.

A fourth person, an elderly woman who was found injured at the scene, was later pronounced dead Friday, police said.

Citing investigative sources, NHK said police in Nagano requested the Metropolitan Police Department to dispatch a “special investigation team” specialising in dealing with barricading incidents to the site.

Police are investigating the possible motive for the attack and how the weapon was obtained.

Earlier, authorities had urged people to stay indoors in the semi-rural area of central Japan after the rampage began Thursday afternoon. They had designated an “evacuation zone” with a radius of 300 meters around the scene of the incident.

Gun violence remains extremely rare in Japan, and shootings of multiple police officers are even rarer, with the last incident taking place more than 30 years ago.

Japan, a country of 125 million people, has one of the lowest rates of gun crimes in the world due to its extremely strict gun control laws. But the country was rocked by the killing of ex-Prime Minister Shinzo Abe last July.

Abe, the country’s longest-serving prime minister, was shot dead during a campaign speech in Nara in July. His murder shocked Japan and the international community and also sparked questions about whether enough security was in place to protect him despite the country’s track record of being a safe place.