Police are investigating the armed robbery of a clothes store in Sydney yesterday.

About 4:15pm, Thursday 23 August 2012, two men entered the store located within a shopping centre on George Street.

Once inside the premises the men, who were armed with a knife, approached a female sales assistant and made demands for cash from the register.

The shop owner attempted to intervene in the robbery and prevent the men from stealing cash but was unsuccessful.

The pair took a small sum of cash from the register and ran out of the store towards Jamison Street where they were chased by the sales assistant.

Police were patrolling nearby and were flagged down by members of the public. Despite a search of the area they were unable to locate the two robbers.

The men have been described as being of Caucasian appearance, aged in their mid 20s to 30s with dishevelled clothing and missing teeth.

One of the men had a stocky/solid build while his accomplice is described as being taller with a thin build.