The robbery happened just before 8pm yesterday, 11 April, at the Newmans Collard Recreational Ground.
The victim, a 17-year-old boy, was at the recreational ground when he was approached by an unknown man who asked for a lighter.
His bag was stolen and he was assaulted, he received minor injuries as a result.
Officers investigating the robbery would ask that anyone with information phone 101 with reference 44210136688. Alternatively, you can phone Crimestoppers 100% anonymously on 0800 555 111.