Police are investigating the armed robbery of a service station in the Hunter region.

About 8.30pm yesterday (Wednesday 12 August 2015), two men entered a service station on Main Road, Heddon Greta and threatened the attendant with a firearm and a metal bar, demanding cash.

A small amount of cash was given to the men before they ran from the scene. The attendant was uninjured.

One of the men is described as aged in his late teens, 170cm tall, brown hair and wearing a blue/silver coloured jumper and brown pants. He was armed with a metal bar.

The other male is described as aged in his late teens, 180cm tall, blonde hair and wearing a black jumper and jeans. He was armed with a small black handgun.

Both males had their face covered.

Police from Central Hunter Local Area Command and the Dog Squad attended however the offenders were not located.