Police are seeking public assistance following an armed robbery in Sydney’s south-west overnight.

About 10.30pm (Thursday 1 November 2012), two men entered the service station on the Hume Highway, Lansvale, armed with a firearm.

They threatened the 19-year-old male employee and demanded money from the register.

The staff member complied and the pair fled on foot with a sum of cash.

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

The first man is described as being about 180cm tall, with a muscular build and broad Australian accent. He was wearing a grey hooded jumper, black track pants, joggers and holding a black handgun.

The second man is described as being about 170cm tall and medium build. He was wearing a brown jumper, dark blue track pants and joggers.