Thames Valley Police is releasing CCTV footage following an attempted robbery in Milton Keynes, which occurred last month.
At 5.53pm on Monday 6 January, three men entered the Station Square Premier news in Elder Gate, Central Milton Keynes.
The offenders left the shop without taking any property.
A member of staff, a man in his forties, suffered a minor head injury during the incident, but he did not require hospital treatment.
Investigating officer Detective Constable Ian O’Bryne, based at Milton Keynes police station, said: “I am releasing this footage as I believe someone will recognise the men involved.
“This was a distressing incident for the victim, who, along with a member of the public, fought back, preventing the offenders from taking anything.
“I am appealing to anybody who recognises any of the men in this footage to contact the 24-hour non-emergency number 101, quoting reference number 43200005919.
“You can also make a report online, or if you wish to remain anonymous, call the independent charity Crimestoppers on 0800 555 111.”