Yusuf Mohamed, 18, from Hammersmith, was attacked in Uxbridge Road, Shepherd’s Bush at around 9.20pm last night.
Despite the efforts of paramedics, he was pronounced dead at the scene a short time later.
A family friend of Yusuf said he was stabbed in the chest outside the local greengrocer and fled inside the shop after being sent to “buy milk for his mum”, a friend said.
They said: “His mum had sent him out to buy milk. He only lives a few minutes from here and that’s what he was doing.
“The boy that stabbed him was about 15 years old.
“He was stabbed outside and he ran into the shop to the back where there are stairs to the basement to get away, and the [boy] ran after him and stabbed him again.
“It’s shocking. His mum collapsed when she heard.”
Witnesses said the teen was stabbed to death in a west London shop as he tried to hide after a fight.
Resident Derek Parks said the teen had gone into the store “for cover” but was followed by a man who had a knife and stabbed him.
The Met said it was looking for “two males, possibly in their teens” who ran away in the direction of Wormholt Park.
“His mum had sent him out to buy milk”
Mr Parks said the fight happened “outside the shop doorway and the gentleman came in from outside”.
“The guy who got stabbed went towards the basement of the shop and was hiding,” the 64-year-old said.
Detective Inspector Luke Wyllie said: “A young man’s life has been tragically cut short.
“Our thoughts are with his friends and family at this very difficult time. We are doing everything we can to apprehend those involved.
“Extra police and specialist units are working on the ground now to build a clearer picture of what took place and work to protect and reassure those in the local community.”
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