A masked man armed with a knife and a rifle killed a woman and two police officers in the central Japanese prefecture of Nagano, according to state broadcaster NHK, citing police reports.
A fourth person was injured. The man, who was wearing camouflage clothing, a mask and sunglasses, stabbed the woman and then opened fire with what appeared to be a hunting rifle when police arrived.
The three victims were taken to a hospital, where they died. Police said the attacker was now barricaded in a building.