Ilkeston detectives are appealing for witnesses after a 14-year-old boy suffered a fractured cheekbone in an assault on a Kirk Hallam skate park last month.
The incident happened at the skate park on Windsor Crescent at around 3.50pm on Monday, April 10.
The victim was using the park with one of his friends when he was approached by a group of young males.
After a short altercation, he was punched several times in the head.
The offender was white, aged between 14 and 16, about 5ft 6ins tall, of skinny build and with short brown hair.
He was wearing a black Adidas jumper, skinny jeans, black trainers and had a gold coloured chain round his neck.
Witnesses or anyone with information should call DC Mike Novak on 101, quoting incident number 17000155493, or Crimestopers anonymously on 0800 555 111.