Police in the central Japanese prefecture of Nagano say a man with what appeared to be a hunting rifle and a knife has killed a woman and two officers.

The police say they received a report that a man stabbed a woman in the city of Nakano on Thursday.

They say that after officers arrived on the scene, the man opened fire at them.

The police also say the man hurt four people, including the woman and the two officers, and is holed up in a building in the city.

Authorities are warning nearby residents to stay indoors as the man is reportedly still armed.