A 13-year-old boy was punched in the ribs by two older teenagers following a confrontation on Kent Road South, Northampton.
Between 5pm and 5.45pm on Monday, August 14, the victim was cycling with friends along Kent Road South, Upton, at the junction with Jennings Close, near the pocket park.
He was approached by a gang of older boys, and following a short verbal exchange, two of them punched the victim in the ribs, before making off.
One of the offenders is described as mixed race, around 16 years of age with an average build and 6ft tall.
A police spokeswoman said: "He had afro-styled hair that was very short on the sides but long and flimsy on the top. He had brown eyes, a small light moustache and was wearing a green coloured top and trousers."
The second offender is described as mixed race, 15 or 16 years old, with a skinny but muscly build and around 5ft 9ins tall.
He had black hair which was shaved on the sides, but thick and curly on top and with vibrant blonde highlights. He also had overlapping front teeth.
This suspect was wearing a grey coloured North Face jumper and grey bottoms.
Anyone with information can contact Northamptonshire Police on 101. Alternatively, they can call the independent charity Crimestoppers anonymously on 0800 555 111.