A 32 year-old woman is in a life threatening condition in hospital after being stabbed at the Notting Hill Carnival, the Metropolitan Police said.
The force said on Sunday it was aware of three stabbings at the annual west London celebrations, with a 29-year-old man in hospital with non-life threatening injuries, and a 24-year-old man also stabbed whose condition had yet to be confirmed.
Fifteen officers were assaulted, although none were seriously injured, and 90 arrests had been made on Sunday, police said.
A force spokesman said: “Hundreds of thousands of people came to Notting Hill Carnival today to enjoy a fantastic celebration.
“Our officers have been on duty working to keep them sae as part of a very carefully planned policing operation.
“Regrettably, a minority came to commit crime and engage in violence.”
Arrests were made for a range of alleged crimes including assault on an emergency worker, assault, possession with intent to supply, sexual offences and robbery, the police said.
Suspects were also arrested for drugs possession, theft, possession of a nitrous oxide and public order offences.
Earlier, the force said it had been granted greater search powers to prevent further violence after a man was stabbed and knives had been recovered.
The carnival is Europe’s biggest street party and is billed by organisers as “the greatest community-led event on the planet” .
Around a million people are expected to attend across the bank holiday weekend, with about 7,000 officers on duty for the celebrations.
The police said the order also gives officers the power to demand the removal of face coverings being used to conceal a person’s identity and anyone refusing can be arrested.
Earlier on Sunday, the streets of west London came alive with colour, costumes, dancing and music and thousands of revellers enjoyed the celebrations.
During Sunday’s Children and Families’ Day, youngsters were dancing in the streets along the parade route wearing bright and intricate costumes.
The annual celebration of Caribbean heritage, arts and culture has been running for more than 50 years.
The main parade is held on Monday, described by organisers as the climax of the carnival with “party vibes”.