West Midlands Police said the incident took place on Maple Green shortly after 6pm on Friday (July 31). It is believed that the boy was knocked off his bike and stamped on by a group carrying weapons. A spokesperson for West Midlands Police said: " We’re investigating after a 13-year-old boy was assaulted by a group carrying weapons on Maple Green, Dudley. "The incident took place shortly after 6pm on Friday. The boy was believed to have been knocked off his bike and stamped on.