Police are appealing for information after an armed robbery at a mixed business in Sydney’s west.

 About 4.40pm today (Thursday 8 September 2011), a male has entered the store on Antoine Street at Rydalmere.

 He threatened the male staff member with a firearm and demanded money.

 He escaped with a sum of cash and a laptop computer.

 A bystander chased the man who was last seen jumping over fences in Nowill Street

 The staff member was assessed by ambulance paramedics at the scene but did not require further medical treatment.

 The man has been described to police as being of Pacific Islander appearance, aged in his 30s and of muscular build

When he was last seen the man was green cargo shorts, a dark hooded jumper and white running shoes. The man kept his face covered during the robbery.

 An air and ground search for the man is continuing.