A gang armed with a knife robbed a Wellingborough shop after demanding staff open the tills.
Three men with their faces covered stormed into the Co-op in Farm Road at about 9.30pm on Thursday (October 31) before one produced the 7in blade.
One till was forced open and another opened by staff and the trio stole cash, spirits and cigarettes before they fled towards the Hemmingwell estate.
A police spokesman said: "The first suspect is described as 5ft 9in, of slim build, wearing a green coat with white stripes down both arms, dark tracksuit bottoms and wearing a black bandana with a white pattern covering his face.
"He carried a seven-inch knife with a curved tip and a brown handle with silver dots on it.
"The second suspect is described as 5ft 10in, of slim build, wearing a black/grey hooded top, a full balaclava covering his face, dark tracksuit bottoms, Nike Air Max trainers and carrying a black rucksack on his chest.
"The third suspect is described as 5ft 9in, of slim build, wearing a black Nike hooded top with a white tick and writing on the front, a full balaclava and tracksuit bottoms.
"All three suspects wore gloves."
Anyone with information about the shocking incident is asked to call Northamptonshire Police on 101, or Crimestoppers anonymously on 0800 555111.