A teenage boy "could have lost his life" after an attack on New Year's Day.
Police were called to Durham Road just after 2am on January 1 and are now investigating the racially aggravated assaulted.
A spokesman for the Met said: "The victim, a man aged 18, was punched by another man - the suspect then walked off down Durham Road.
"Due to comments made by the suspect, this attack is being treated as racially aggravated."
Anyone with information is asked to contact police on 101 on 1446/1Jan or call Crimestoppers anonymously on 0800 555 111.