A man has been arrested after four people were killed in a rare shooting and stabbing attack in Japan.

The alleged assailant stabbed a woman and shot two policemen with a hunting rifle in Nagano prefecture. A fourth death was later confirmed.

Police have named the suspect as Masanori Aoki, the 31-year-old son of a local politician.

Gun violence remains extremely rare in japan, despite the killing of Ex-Prime Minister Shinzo Abe in July last year.