A crime scene has been established at a Colyton service station following an armed robbery overnight.
About 1.30am today (Wednesday,January 29), a man entered the service station on the Great Western Highway and threatened a male employee, 23, with a gun.
The offender demanded money and cigarettes and fled the store.
He was last seen running towards Bennett Road.
No shots were fired and no one was hurt during the incident.
St Marys detectives would like to speak to a man described as 180 centimetres tall and medium build.
He was wearing a black baseball cap, three quarter shorts and a black top.
Police are urging anyone with information about this incident to call Crime Stoppers on 1800 333 000