Police are investigating an armed robbery in Sydney’s south-west overnight.

About 10.35pm, two men entered a service station on Waterloo Road, Greenacre, and threatened the male attendant with a machete and a baseball bat.

They were provided an amount of cash, and also stole a box of cigarettes and the attendant’s mobile phone before fleeing the scene.

They were last seen on foot in Ivy Street, Greenacre.

Both men are described as being of Mediterranean/Middle Eastern appearance, 16-17 years old, with muscular builds. One was wearing a white t-shirt with a hood, a black and white bandana over his face, and black shorts.

The other offender was wearing a black long sleeved shirt with a hood, as well as a black balaclava and black shorts.

Police from Bankstown Local Area Command attended the scene and established a crime scene.

The attendant was uninjured in the incident.