Police are hunting a man after a 17-year-old boy was stabbed near an east London train station
Officers have issued the CCTV image of a man in a distinctive black and purple jacket following the attack in Stoke Newington at about 9.30am on Wednesday.
The seriously injured young victim was found with a stab wound on nearby Darville Road a short time later, police said.
He was treated by paramedics at the scene before being rushed to hospital, where his condition is described as "serious".
Medics initially thought his injuries were life-threatening, but police now say he is now expected to survive the brutal attack.
Detective Constable Paul Cudby said: “We need anyone who was at Rectory Road station or in the surrounding area and witnessed this incident to come forward.
“I am particularly keen to speak to the man in the image as I believe he has important information.”
Contact British Transport Police on 0800 40 50 40, or text 61016, quoting reference 299 of 11/5/16.
