Another boy, also 17, was found injured with Yeray but has since been discharged from hospital, police said.
Four other boys have been charged in connection with the incident: a 15-year-old, a 16-year-old and two 17-year-olds.
The 15-year-old appeared at the Old Bailey while the other four all appeared at Bromley Magistrates’ Court on Monday, 8 September.
Police are still appealing for witnesses to the incident, which happened outside a McDonalds on Old Kent Road, including anyone who was driving and may have dashcam footage.