Mercedes used in two Gold Coast robberies

A man armed with a knife has threatened shop assistants on the Gold Coast before escaping in a Mercedes Coupe.

A man and a woman were threatened with a knife at a shop in Southport on Wednesday evening.

The robber demanded cigarettes but ran off after the store attendant tried to grab him, police said.

He was last seen driving away in a stolen Mercedes with registration 611 SGZ.

About two hours later at Worongary, a man armed with a knife entered a shop on San Fernando Drive and demanded cash and cigarettes, which the attendant gave him.

The robber was last seen getting into a white Mercedes Coupe.

Police did not say if the two incidents were related, but have appealed for witnesses.