A manhunt is intensifying for the gunman who allegedly killed a bartender and three patrons at a bar in southwestern Montana, authorities said. Michael Paul Brown allegedly opened fire around 10:30 a.m. local time Friday at The Owl Bar in Anaconda, a city of about 9,000 people in southwestern Montana, according to the Montana Department of Justice.

Police say the suspect was "a regular" at the bar where he opened fire, and that a bartender and three patrons were among the victims.

A massive manhunt is underway in western Montana for Michael Paul Brown, 45, who allegedly killed four people at The Owl Bar in Anaconda on Friday morning. Brown, a military veteran, fled the scene in a white pickup truck but later abandoned the vehicle.