Knife-wielding robbers targeted a mini-supermarket in Huntingdon.
Two men entered Tesco Express, in Wertheim Way, at just after 10pm on Tuesday (October 8). One of the men is reported to have threatened a member of staff with a knife before demanding money.
Police said the men took a "large amount of cash in notes" from the till and fled.
A spokesman for Cambridgeshire police said: "The man with the knife was described as wearing a dark tracksuit and grey trainers with a blue bucket hat, and the second man as wearing black trainers and a dark hoodie."
Anyone with information should call police on 101, quoting crime reference number 35/72178/19.