A man was taken to hospital for treatment to a head wound after he was hit over the head by a gang in Wellingborough.
The victim was in Cambridge Street when three people - a teenage boy, a man and a woman on a scooter - came up to him, one of whom hit him with some metal.
The injured man had to seek help from a nearby barber after the attack and Northamptonshire Police are asking for witnesses to the attack to help.
A spokesman for Northants Police said: "Officers are asking witnesses to a serious assault in Wellingborough to get in touch.
"Between 2.30pm and 3pm on Sunday, July 4, a man was in Cambridge Street when he was approached by three people, one of whom then struck him over the head with a metal object, causing a deep wound to his scalp.
"The man sought help in a nearby barbers in Market Street before he was taken to hospital for stitches.
"The first suspect is described as a mixed race boy aged between 15 and 17, over 6ft and of stocky build. He wore a black tracksuit and had dark coloured hair.
"The second suspect is believed to be a white male, around 5ft 7in and of chubby build. He wore a grey or beige coloured tracksuit and had brown hair.
"The third suspect is described as a white female, of slim build with long dark coloured hair. She wore a red top, blue jeans and was on a scooter."
Anyone who saw the incident or who has information about it is asked to call Northamptonshire Police on 101 quoting incident number 21999373771.