Thieves brandishing a hammer stole cash and cigarettes from a Tesco store in Rochdale.
The robbery happened at the store in the Pennine Precinct on Newhey Road in Milnrow just before 9.30pm on 8 February 2013.
Three offenders went into the store, one of whom was wielding a hammer, and threatened a member of staff on the tills.
Frightened, he ran to the staff room but was chased by the offender with the weapon, who continued to make demands and wave the hammer in an aggressive way.
Eventually, the three men stole cash and cigarettes before fleeing.
No-one was injured but the staff inside were badly shaken up.
The offender with the hammer is described as being white, of a medium build and wearing a dark hooded top with the hood pulled up. He used a dark scarf to conceal his face. The hammer was said to be about 12inches long.
Police are now appealing to anyone with information to come forward.
Detective Constable Donna Rollinson said: "These offenders used as much fear and intimidation as possible to threaten the staff inside the store just to get their hands on some cigarettes and cash.
"Luckily, no-one was physically injured but clearly the emotional distress these men caused with the threats of violence was huge.
"I would therefore appeal to anyone who can help us find these men to come forward immediately, If you were in the vicinity and witnessed any suspicious activity, or perhaps saw these men going into or out of the store, then we need to hear from you."
Anyone with information is asked to call police on 0161 856 8716 or the independent charity Crimestoppers, anonymously, on 0800 555 111.