A man was punched to the face twice in Kettering.
The victim was punched by another man in Abacus, Dalkeith Place, Kettering, close to the downstairs bar.
The victim fell to the floor.
The incident is believed to have happened at about 3am on Monday, May 4.
Anyone with any information can call Northamptonshire Police on 101.
Alternatively, they can call the independent charity Crimestoppers anonymously on 0800 555 111.