The death of a teenager stabbed in east London on Wednesday night brings the total number of youths killed on the streets of the capital to eight this year.
News of the death comes as it emerged London's Air Ambulance service is now being called out to more stabbings and shootings than road traffic accidents for the first time in its 30-year history.
The 18-year-old man was chased down Padnell Road in Chadwell Heath on Wednesday night by what police have said may have been "a number of suspects" before he was attacked.
He was taken to hospital but died in the early hours of Thursday morning. So far one man has been arrested in connection with the killing and investigators are appealing for witnesses.
The victim, who has yet to be identified, is the eighth teenager to be killed in London this year and brings the total number of murders to 31.
The incident is the latest in a rising wave of knife crime - in the year to September 2017, England and Wales saw a rise of 21% in recorded crimes involving a knife, including a 13% rise in homicides.
Statistics released on Thursday by London's Air Ambulance revealed stabbings and shootings now make up 31% of its callouts, while road traffic accidents account for 30%.
It treated 560 victims of violent crime in 2017 out of a total of 1,797 critically injured patients.