Police say the armed robbery took place in Killinchy, Co Down, on Sunday, March 26.
At around 7.30 pm it was reported that a man, armed with a hammer, entered the shop on Comber Road.
He threatened a female member of staff before making off with a sum of cash and cigarettes.
It is believed he made off in a black coloured car accompanied by two other males.
A car matching the description was observed by Police in north Belfast around 9pm and was subsequently stopped on Clifton Park Avenue.
The three males, aged 26, 27 and 28, were arrested on suspicion of robbery.
All remain in the PACE custody suite at Musgrave PSNI station for questioning.
Detectives are appealing for anyone who witnessed the robbery or anyone with any information that can assist with the investigation to contact detectives in Bangor on 101 quoting reference number 998 of 26/03/17.
Information can also be passed anonymously via the independent charity Crimestoppers on 0800 555 111.