Police are investigating the armed robbery of a convenience store in Coorparoo this afternoon.

Preliminary information suggests around 1.30pm a man has entered the business on Old Cleveland Road armed with a piece of wood and demanded money from the female owner.

The man has then struck the 52-year-old woman on her arm and the side of her head with the wood before taking her purse and fleeing the store.

The victim sustained bruising to her arm and a minor facial injury and was assessed by ambulance officers at the scene.

The man is described as Caucasian in appearance with a muscular build, around 170cm tall and was wearing a black singlet with a white symbol on front and multi-coloured board shorts.