Two women working in a Brandon shop refused to hand over safe keys when they were threatened by three armed robbers on Christmas Eve.
The three raiders, one armed with a metal bar or spike, went into the Londis Store on Thetford Road at about 0700 GMT in Wednesday.
They pushed two women working in the shop into a back room, and demanded the keys to a safe.
When the women refused, the men took a quantity of cigarettes, which they carried off in black bin bags.
All three robbers are said to be white and around 30 years old.
It is thought at least one of them left on foot, and headed in the direction of the town's Warren Estate.
Suffolk Police are investigating the incident.