Grocery on North Shore Road in Devonshire last night.

The man threatened a female cashier with the knife before taking money from the cash register.

The frightened shop assistant was shocked but unhurt as she stood back to allow the thief to help himself to an unknown amount of cash.

A Police spokesman said last night that the robbery took place at 6 p.m. and the thief ran off toward Roberts Avenue. Detectives from Central CID are investigating the crime.

A staff member at the store refused to comment last night but said it was a minor incident.