The Telegraph of Macon reports that the video, posted Sunday on YouTube, is titled "Rookie prank."
Fire Chief Marvin Riggins said he's "deeply saddened" by the video, which shows scared firefighters face-down on the ground as a man with a yellow bandana over his face waves a gun.
At one point, the gunman leads a firefighter away from his spot on the ground. Moments later, the sound of a gunshot is heard.
Bibb County Commissioner Lonzy Edwards says the video comes at a time when local leaders have been trying to find solutions to recent gun violence.