According to Houston police, the officer asked the men to leave the bar during the course of the night. They left, but things took a turn for the worse at closing time.
Investigators said the men waited for the officer to get off work and started following him, driving erratically and getting close to his vehicle.
The suspects stopped at a red light on the East Freeway feeder at Wayside and the officer approached their car, asking them what was going on.
One of the men reportedly responded, saying they were drunk and couldn't drive.
Police said the officer then followed the men to a nearby gas station to let them call someone for a ride. That's when one of the men pulled a gun on him.
According to officials, the officer then discharged his weapon and hit a window. The suspects drove away.
Investigators believe no one was injured, but they are now looking for the men involved.