Police in Bletchley have released CCTV images of a man they want to speak to following a robbery.
The incident occurred at around 9.30pm on Thursday in the Co-op on Water Eaton Road.
The offender entered the store, walked behind the till and threatened a member of staff with a knife with a gold handle.
The offender asked the staff member to open the till and put the money into a bag.
The offender was spooked by other staff members and left the store on foot towards Water Eaton Road.
The victim was not injured.
Investigating officer Detective Constable Daisy Hincks, based at Milton Keynes police station, said: “We would like to appeal to anybody who may know who the man in these images is, or if you are the man, to please get in touch as you may have vital information about this incident.
“You can get in touch by either making a report online or by calling 101, quoting reference number 43230050779.
“Alternatively, for 100% anonymity, you can also call the independent charity Crimestoppers on 0800 555 111.”