Investigations are continuing following the armed robbery of a service station in Sydney’s south yesterday.

About 6.45pm (Tuesday 22 May 2012) a man walked in to the service station on the Princes Highway, Arncliffe, and threatened a 30-year-old male staff member with a firearm, demanding cash.

A 24-year-old female customer was also threatened by the man.

The staff member handed over a sum of cash before the armed man ran from the service station. He was last seen heading south on the Princes Highway.

Police were notified and officers attached to St George Local Area Command are investigating the incident.

The man has been described as being approximately 175cm tall, aged in his early 20s, with a slim build, and was wearing a black tracksuit and black balaclava at the time.