A gunman who was locked in a standoff with police at an apartment block in the city of Wakayama died late Wednesday after ending the 17½-hour siege with a self-inflicted gunshot to the stomach.

Former construction worker Yasuhide Mizobata, 45, was taken to the hospital by ambulance but died about two hours later. He is suspected of killing a former colleague and injuring three others by shooting them during a meeting at a construction firm in the city on Monday.

Mizobata had kept the officers at bay by occasionally firing the gun while yelling about a failed business. The police responded by evacuating residents and trying to get him to surrender.