Police are continuing to investigate two armed robberies at businesses in Fortitude Valley yesterday which they believe may be linked.

Around 11.05am a man entered a retail store on Ann Street and demanded money from the attendant stating he was armed with a knife.

No money was obtained and the man left the store when a member of the public entered the premises.

Around 11.40am a man attended a Brunswick Street café before demanding a female staff member hand over cash from the till while claiming he was armed with a knife.

The man stole a quantity of cash and fled the scene.

The man is described as being Caucasian in appearance, about 180cm tall with a solid build and blonde hair. He was wearing a white t-shirt, blue trousers, and was carrying a backpack.

No one was physically injured during the incidents.