Police are appealing for witnesses and information following a fatal stabbing in Isleworth.
Officers were called at around 22:35hrs on Friday, 22 March after reports that a teenager had been stabbed near flats in Union Lane, Isleworth.
On arrival, officers found the 17-year-old victim suffering stab injuries outside the flats. London Ambulance Service also attended and administered first aid but the victim died at the scene a short time later.
Next of kin have been informed; formal identification awaits.
A post-mortem examination will be scheduled in due course.
An investigation is underway by detectives from the Homicide and Major Crime Command led by Detective Chief Inspector Richard Leonard. He said:
"Our enquiries have established that the victim was in Syon Park close to the flats with a group of other people.
"A vehicle pulled up and a group of males got out. They chased the victim and attacked him in Union Lane.
"I need to speak to anyone who was in the park or the surrounding area at around 10:30pm last night and who has information that could assist this investigation. They should get in contact immediately."
At this early stage, officers retain an open mind as to the motive.
There has been no arrest; enquiries continue.
A crime scene remains in place in Union Lane and local officers remain in the area and are available should any residents have concerns.
Any witnesses or anyone with information that may assist police is urged to call 020 8721 4622 or call 101, quoting CAD 8396/22Mar. To remain anonymous call Crimestoppers on 0800 555 111.
If any young people have information about violence or knife crime, they can visit http://www.fearless.org/ where they can pass on information anonymously. Fearless is part of the Crimestoppers charity, and is also independent of the police.