A young man has suffered potentially life-changing injuries after he was stabbed in a west London park.
Police were scrambled to Heston Park, Hounslow, at 5.40pm on Saturday where the victim was found slumped with serious injuries.
He was taken to hospital where he remains.
A knife was recovered at the crime scene as search teams scoured the area for clues.
Forensics experts have been at the scene while officers are trawling CCTV, dashcam and doorbell footage from the surrounding area.
The stabbing took place in the early evening when families and dog walkers would have been using the park,
A Met police statement said: “Police were called at about 17:40hrs on Saturday, 7 September to reports of a man stabbed in Heston Park in Hounslow.
“Emergency services attended. The 21-year-old man was taken to hospital by the London Ambulance Service. His injuries have been assessed as not life threatening but potentially life-changing.
“A crime scene is in place. A knife has been recovered.
“There have been no arrests and enquiries continue.”
The incident came as Hollywood actor Idris Elba on Monday joined the Prime Minister in Downing Street to launch a new effort to tackle knife crime.
Elba, an anti-knife crime campaigner who starred in the Wire and Luther, was launching a coalition which aims to stop young people from being dragged into violent gangs.
It is bringing together campaign groups, families of people who have lost their lives to knife crime, and young people who have been affected by it – as well as Elba and Home Secretary Yvette Cooper.
Technology companies, sporting organisations, the health service, and the police are also involved in what is expected to the first annual knife crime summit.
The coalition will work with experts to develop an understanding of what causes young people to be dragged into knife crime.
Elba said: “We need to tackle the root causes of knife crime, not just the symptoms. The coalition is a positive step toward rehabilitating our communities from the inside out.”