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.

Those killed on Friday were a bartender and three patrons, ranging in age from 59 to 74, the authorities said. The suspect fled into the nearby foothills.

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.