MACON, Ga. (AP) - Macon-Bibb County's fire chief says five of the seven firefighters pictured in a controversial video were in on the prank, and two rookies were not.

The video, titled "Rookie prank," shows a masked man bursting into a fire station and threatening firefighters with a gun. It was posted Sunday on YouTube.

The Telegraph of Macon reports (http://bit.ly/pFWFLV) that Fire Chief Marvin Riggins said he expects disciplinary action will be taken by Wednesday.

Riggins said he's appalled 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.