A teenager who died after being stabbed in the street has been described as a "timid young man" who was on the "periphery" of a gang.
Hani Abou El Kheir, 16, was set upon on the edge of Pimlico by a gang reported to have been wielding swords and knives.
Emergency services battled to save the teenager's life as he lay bleeding in Lupus Street, but he died a few hours later in hospital.
Scotland Yard said police were "retaining an open mind regarding any motive at this stage" and confirmed a post-mortem examination into his death will take place at noon. No arrests have been made.
It has since emerged that Hani had become known to drugs intervention workers, and was believed to be "on the periphery" of local gangs.
David Savizon, who works for the Westminster Council's Your Choice anti-gangs programme, said Hani's name had been flagged up to drugs workers last week, and he was due to get a visit from outreach workers if it came up again.
Mr Savizon, 34, said: "Unfortunately I wasn't able to meet him. He wasn't deemed significant in terms of being in a gang. He was mentioned as someone on the periphery."
Mr Savizon, who has 12 years of experience working with youngsters at risk of joining gangs, added: "It was more of a bookmark just to see where this young person was.
"Everything I have heard about him ... he was a very timid young man."
The suspected drugs-related attack happened at 7pm on Sunday near Pimlico Underground station. Lupus Street is bordered by extensive council estates on one side and is home to Pimlico Academy.
The Churchill Gardens estate where Hani lived has become a drugs black spot in the last year.
Children as young 10 are paid "tens of pounds" to stash drugs and ferry them around.
Hani's mother, Pauline Hickey, who lives in Gilbert House, 100 yards from the crime scene, was said to be "heartbroken" and is being comforted by friends and a family liaison officer.
It is believed she or a female friend tried to comfort the teenager as he fought for his life.
Mohammed Alzubaidi, 49, from nearby Peabody Close, said his friend witnessed a gang of black and white teenagers carrying out the attack.
"He said they were carrying knives, some of them with wide swords. He said the victim was screaming and trying to get away."