Officers were called to Highbury Fields, Islington, shortly 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. No arrests have been made and inquiries into the circumstances are continuing, Scotland Yard said. A cordon surrounding Highbury Fields, which covers the entire park, will be in place for “at least the rest of the day” and possibly for a few days, police at the scene said. Albina, a local resident who only wanted to be known by her first name, said her daughter saw a gang of about 70 youths approaching the park before the stabbing. She said her daughter, a teacher, was walking with her 15-year-old son at about 7.45pm. when he saw the group, which he assumed included children as young as 15. Kimberley Patton-Bragg and Michael Bragg, who were visiting London from New Orleans, said they saw the police presence as a group of between 15 and 20 youths “heated up” at about 7pm. Patton-Bragg said: “The kids – they were definitely kids – were running rampant and it was definitely getting hot.” The couple were sitting inside their Airbnb, which overlooks the park, with the windows open when they saw the situation unfold. Bragg said: “You could feel it building, at some point the teams got bigger.” Anyone with information is asked to contact police on 101 or tweet @MetCC quoting CAD 7948/4Aug. Alternatively, contact Crimestoppers anonymously on 0800 555 111.