Two teenagers were stabbed multiple times in a park in West London last night (7 August), leaving a 15-year-old in a life threatening condition.
Emergency services were called shortly after 8.30pm to West Harrow Park.
London Ambulance Service also treated a 17-year-old boy who had knife wounds at the scene before he was taken to hospital.
The other boy, 15, received serious stab wounds and was taken to A&E and is now in a critical condition.
An air ambulance helicopter was seen attending the scene and then heading off while the area was cordoned off.
A crime scene remains in place and no arrests have been made so far.