Police investigating the murder of a 17-year-old boy near a London Tube station have named the victim.
Scotland Yard said Malcolm Mide-Madariola from Peckham was a student at a college in Clapham.
He was stabbed near Clapham South Tube station on Balham Hill at around 4.35pm on Friday.
The victim was taken to hospital but died less than an hour later.
Next of kin have been informed and a post-mortem examination will be held, the Met said. No arrests have been made.
Robin Pritchard, who witnessed the aftermath of the stabbing, said on Friday he moved through a crowd and saw the victim lying in a pool of blood while someone provided CPR.
“I saw the guy on the floor, a pool of blood like he’d been stabbed in the stomach, his clothes were soaked,” the 47-year-old said.
“It was strangely calm and quiet. I think everyone was in shock. Lots of kids there from the local college.
“All I really registered were grey tracksuit bottoms which were soaked with a pool of blood coming from his waist like he’d been stabbed in the stomach.”
Another witness, who did not want to be named, said he saw “a bunch of guys” shouting and appearing agitated, with one carrying a large knife.
He added that the area is usually noisy after students leave a nearby college.
He said: “I had no idea it was different to any other time the students get a bit noisy, until I saw the knife as I was literally passing them.”
Detective Chief Inspector John Massey, who is leading the of the Homicide and Major Crime Command, which is conducting the investigation, said in a statement: “We are confident that our investigation will lead us to the person or people responsible, but we do need to speak with more witnesses and I am appealing for anyone with information to come forward.
“The stabbing in Balham Hill followed an altercation a few minutes earlier involving two small groups of young males near to Clapham South Underground station. However I don’t believe anyone involved had travelled on the tube.”
He added: “No arrests have been made at this stage and urgent enquiries are ongoing.”
Mr Mide-Madariola’s killing came less than a day after 15-year-old Jay Hughes was stabbed to death in a “premeditated attack” near a chicken shop in Bellingham, south-east London.
London Mayor Sadiq Khan offered his condolences to the families, saying the teenagers’ deaths were “a terrible waste of young lives”.
The stabbings came amid ongoing debate about the effect of police budget cuts and what the police’s priorities should be.
Mr Khan has previously blamed rising violence on £700m cuts to the Met’s budget over seven years, with more expected to come.
On Friday, Mr Khan announced the latest measure in the “public health approach” to tackling violence, with a review of the most serious offences since 2014 to discover the trends behind attack
Metropolitan Police Commissioner Cressida Dick said on Friday ”stretched” forces must focus on serious violence and drug gangs rather than non-criminal acts of misogyny.
Additional reporting by Press Association