They have released these CCTV stills of two men they would like to speak to in connection with the attack.
Two men believed to be in their 30s entered the shop at about 7.45pm and assaulted a man inside the premises before starting a small fire and leaving the scene.
Both men wore balaclavas during the attack. Their victim required medical treatment at the scene.
Anyone with information is asked to call 101 and quote crime reference number 5216039860.