An 18-year-old man is "incredibly fortunate" to be alive after he was stabbed in a park in Ilford.
The victim was approached by three men, of a similar age, in Seven Kings Park on Aldborough Road South at about 15:30 on 2 December.
The suspects asked him for a cigarette before he was attacked and suffered multiple stab wounds.
Detective Constable Jonathan Lam said:
"The victim was incredibly fortunate that the consequences of the attack were not graver.
"It is entirely understandable that having witnessed this, you may be fearful of coming forward, but please, consider making the call to police or Crimestoppers anonymously."
Police believe there may be phone footage of the incident.
One suspect is described as Asian, and was wearing a dark beanie hate.
The two other suspects are described as black and white.