A 15-year-old boy died in a stab wound in north London.
Officers were called to Highbury Fields, Islington, just before 9pm on Thursday, the Metropolitan Police said.
The boy was treated at the scene by paramedics before being taken to hospital, where he died a short time later. There have been no arrests and inquiries into the circumstances are continuing, Scotland Yard said.
A cordon surrounding Highbury Fields, which covers the entire park, will be in place “at least the rest of the day” and possibly a few days, police said at the scene.
Albina, a local resident who wished to be known only by her first name, said her daughter witnessed a gang of around 70 youths approaching the park before the stabbing.
She said her daughter, a teacher, was walking with her 15-year-old son around 7.45 p.m. when she saw the group, which she said included children as young as 15.
Kimberley Patton-Bragg and Michael Bragg, who were visiting London from New Orleans, said they saw a police presence as a group of 15 to 20 youngsters warmed up around 7 p.m.
Patton-Bragg said, “The kids – they were definitely kids – were rambunctious and it was definitely getting heated.”
The couple were sitting inside their Airbnb unit, which faces the park, with the windows open as they saw the situation unfold.
Bragg said, “You could feel it building, at some point the bands got bigger.”
Anyone with information is asked to contact police on 101 or tweet @MetCC and quote CAD 7948/4Aug.
You can also contact Crimestoppers anonymously on 0800 555 111.