A 21-year-old man has died after being stabbed at the Notting Hill Carnival as scenes turned ugly on Monday night.
The Metropolitan Police said that a man, who was stabbed and given first aid by officers, later died in hospital.
A Section 60 order in the area was put in place at 9.24pm on Monday and it will last until 1am, giving police powers to stop and search people without suspicion.
A Metropolitan Police statement said: "At around 8pm on Monday, August 29 officers became aware of a stabbing in Ladbroke Grove, under the Westway flyover.
"Officers provided emergency first aid to the victim - a 21-year-old man - until the arrival of London Ambulance Service paramedics.
"They were able to extract him through significant crowds in challenging circumstances to a waiting ambulance.
"He was taken to a west London hospital where, despite the best efforts of medical staff, he was pronounced dead.
"His next of kin have been informed and are being supported by specialist officers."
Young and old had descended on the Carnival again on Monday with a warm and friendly atmosphere during the day as people were able to party at the event for the first time since the pandemic.
The Adults Day parade saw many attendees dressed in colourful, sparkling costumes to match the dancers.
But by the evening the atmosphere had turned sour with footage emerging on social media of people in fancy dress trading punches.
Clips have been uploaded with stunned people looking on as people brawl while many have commented at the way it ruined the otherwise friendly atmosphere.
One tweeted: “Madness,” while another said: “and that’s why you leave early.”
Dr Alison Heydari, Commander of Local Policing, said that after a "largely positive" atmosphere it turned violent on Monday night.
She said: "The atmosphere over the past two days has been largely positive and good natured as carnival should be.
"Regrettably, on Monday evening we saw a number of violent incidents and a 21-year-old man has lost his life.
"Our thoughts are with his family as they come to terms with their terrible loss.
"A murder investigation is under way, led by homicide detectives from the Met's Specialist Crime Command.
"They will pursue every possible line of inquiry to identify those responsible and bring them to justice.
"There were hundreds of people in the immediate vicinity when this incident took place.
"I would urge anyone who saw anything, who has video footage or who has any other information that could assist officers, to come forward."
People came from around the world to enjoy the Carnival, dressed up for the occasion and celebrating its return after the pandemic.
Pam Small, 54, came from the US for her ninth carnival and was dressed in yellow feathers and an intricate sparkly costume.
She said: "I love everything about it. The people, the culture, the diversity - it's really special to be here."
Clayde Tavernier, 23, was wearing a blue-feathered crown and bystanders stopped to dance and take photos with him.
The Dominican dancer, who attends every year, said: "Carnival is the time to be myself, to express who I am. I came all the way from Dominica to be here and to have fun."
Iona Edesiri Thomson and Neve Kearneg, both 18, from London, were following the parade up Ladbroke Grove while wearing make-up featuring Caribbean green and yellow to represent the Jamaican flag.
Ms Thomson said: "We've been since we were little kids and this is the first time since Covid. The people are so fun and I love the food. People cooking their culture's food is really amazing."
Ms Kearneg added: "Usually Britain is very white but going to the carnival shows we are a multicultural nation and it's also great for tourism, which helps our economy."
Walking in the parade was Rolando Ponde, 34, who was wearing white platform heels and was covered in white, purple and pink feathers and matching diamantes.
He said: "Carnival is special because it introduces people to their roots, to their culture. We have our community here in the UK and at carnival we can all come together."
The Metropolitan Police said that by 7am on Monday there had been 76 arrests for "a variety of different offences".
