Police are appealing for public assistance following a string of armed robberies across south west Sydney this year.

Officers from the Metropolitan Robbery Unit formed Strike Force Agria to investigate at least 12 armed robberies of pizza and Chinese takeaway delivery drivers in the Fairfield, Cabramatta, Edensor Park and Bonnyrigg areas between April 2016 and September 2016.

In each incident, two men armed with knives approach and threaten delivery drivers, demanding money.

The latest incident occurred just after 9pm on Wednesday (14 September 2016), when two unknown men approached a 47-year-old Chinese takeaway delivery man on Fitzpatrick Crescent, Casula.

Police have been told the unknown men armed with knives, demanded money and took cash from the man, before telling him to get in his car and leave the location.

He complied and police were notified.

As investigations continue, detectives would like to speak to two men who may be able to assist them with their inquiries.

The first man is described as being of Caucasian appearance, about 175cm tall, of slim build with short blond hair.

The second man is described as being of Caucasian appearance, about 175cm tall, of slim build and unshaven.

Anyone with information is urged to come forward.