At around 8.10pm three men entered the shop.
Two of the males, one of whom was armed with a hatchet or hammer, jumped over the counter and began emptying tills while the third man brandished a handgun.
The males then fled the shop, two heading in the direction of Sandhurst Gardens and the other Stranmillis Park.
Detectives Sergeant Dolores Black said: “We are keen to speak to witnesses or anyone with information that could assist this investigation.
“We would particularly like to speak to anyone who can identify the males involved or who may have spotted a silver coloured car with three men on board in the area last night. The number to call with information is 101.”
Alternatively if someone would prefer to provide information without giving their name they can call the independent charity Crimestoppers anonymously on 0800 555 111.