Police from Penrith Local Area Command are appealing for public assistance following an armed robbery in Emu Plains this morning.

About 12.20am (Wednesday 8 August 2012), a man entered a service station on the Great Western Highway armed with a firearm.

He threatened the 22-year-old male shop attendant demanding cash from the till.

The attendant handed the man an amount of cash from the register which he took before fleeing the premises.

No-one was injured during the incident.

Police attended and established a crime scene which was examined by investigators.

The man has been described as having a medium build wearing a white hooded jumper, black balaclava, black tracksuit pants, black gloves and white running shoes.