A murder investigation is under way after a teenage boy was shot dead at a “family fun day” event attended by more than 1,000 people in west London. Rene Graham, 15, was pronounced dead at the scene in Emslie Horniman’s Pleasance Park, near Ladbroke Grove, after being found with injuries, the Metropolitan police said. Officers were called at about 7.20pm on Sunday to reports of a shooting and have since arrested four men – two aged 21, one aged 20 and one who is 25 – on suspicion of murder. It is believed more than 1,000 people were attending the annual Park Lime event, organised by the Caribbean Music Association and billed as a “family fun day” featuring live music, games and face painting. Det Ch Supt Christina Jessah said: “A young boy has tragically lost his life and our thoughts remain with his family and friends at this devastating time. We will continue to provide them with specialist support. “This investigation is at an early stage and we are keeping an open mind as to the motive. It will take us some time to establish the facts and this will be our priority in the coming days. “We are keen to speak to other witnesses who were in the area at the time of the shooting. There was an event taking place and it’s possible people may have been taking photos or filming. Please check to see if you have captured anything that may help detectives.” A crime scene remains in place. One bystander, 20, told the Evening Standard: “Everyone was chilling, having a good time when I heard a shot. A guy shot in the air … Then everyone scattered, we ran. When the crowd cleared he shot the boy. He was on the ground. “Everyone was running and taking cover, it was mad.” Another bystander told the newspaper: “I heard two bangs then the boy collapsed on the ground. It looked like he had been hit in the chest. There was sheer panic, everyone was running. The next thing there were sirens and police everywhere. It had been a nice event, no problems, then carnage.” Father Damian Ryan, 43, a priest at a church bordering the park, said: “It was a rammed park and outside it was spilling over as well.” On hearing about the shooting, he said: “I wasn’t in complete shock if I’m completely honest – heartbroken, utterly heartbroken, so saddened and maybe a bit of misplaced anger. Several months ago, there had been a murder … a couple of hundred yards away someone was murdered. “I’ve only been here two years, but other parishioners, people in the community, are saying this is not completely abnormal.” Elizabeth Campbell, leader of Royal Borough of Kensington and Chelsea council, said the shooting was “absolutely horrific and just awful for the family”. She said the council was doing “huge amounts” to reduce violence in the area. “We have detached outreach teams working with the young, we have a huge amount of youth clubs, we have outstanding social work – so we do absolutely everything we can on our side as the council.” The MP for Kensington and Bayswater, Joe Powell, described the attack as “horrific news”. In a statement posted on X, he wrote: “I’m aware of the horrific news that a young boy has been shot and killed in Golborne this evening – and my thoughts are with his family. These senseless acts of violence must stop.” A police cordon remained in place at the scene on Monday morning where forensic officers were seen searching the area and taking photographs. Anyone with information is asked to call 101 or ‘X’ MetCC and quote CAD6343/21Jul or report information anonymously to the independent charity Crimestoppers on 0800 555 111.