A man was stabbed in the leg during an attack which also two men punched in the face.
The three men were assaulted while they were waiting for a taxi outside a house in Gosforth in Wellingborough in the early hours of Sunday (February 14).
They were approached by a group of men sometime between 1am and 1.30am, who then punched two of the victims in the face.
A police spokesman said the third victim was stabbed in the leg with an unknown object.
The offenders all wore darking clothing and most had their faces covered with scarves.
Witnesses, or anyone with information about the attack, can call Northamptonshire Police on 101 or Crimestoppers anonymously on 0800 555111.