Dramatic CCTV footage has been released of terrified store staff being held at knifepoint by two raiders who escaped with around £2,500.
An 11in kitchen knife was brandished by one of the robbers as he and his hooded accomplice burst into a Co-Op store in Old London Road, Brighton.
The knifeman vaulted the counter before bundling three members of staff into a room where they were ordered to hold their hands up and get on the floor.
One of the robbers was then seen grabbing wads of cash from the tills, before the pair were captured escaping at around 9.55pm last December 16.
Detective Constable Julian Harrison-Jones, of Sussex Police, said: "This was an alarming and violent robbery with staff having a near foot-long knife brandished at them and being forced to co-operate with the men.
"Thankfully, they were unhurt, but shaken by their ordeal. We are keen to speak with anyone who may have been a witness or have any information that may assist in identifying these men."
Both men spoke with Irish accents. The first man with the 11in knife is described as white, wearing a black jacket with the hood up, black tracksuit bottoms, black boots and a black scarf over his face.
The second man wore a black top with the hood up, grey tracksuit bottoms and green Nike Air Max trainers. Anyone with information is asked to call Sussex Police on 101, or Crimestoppers on 0800 555 111.