Detectives are appealing for any information following the stabbing of a teenager on the Kingsland Road in Hackney.
The attack took place just before 9 pm on Wednesday, 11 March.
Police were called to the scene after a 19-year-old man collapsed outside cocktail bar Ophelia, just yards from Dalston Junction station.
The man was suffering with severe abdominal injuries.
He was taken to a nearby East London hospital.
He is said to be in a critical condition and is fighting for his life.
The victim was attacked by a large group of males who were last seen heading towards Tottenham Road N1.
No arrests have yet been made, and officers from Trident Gangs Crime Command are appealing to anyone with any information.
Witnesses or anyone has information can call police on 0207 230 9795, the police non-emergency line on 101 or contact Crimestoppers anonymously on 0800 555 111.