A heavy police presence is expected at the second day of Notting Hill Carnival after three people were stabbed on Sunday.
The Metropolitan Police said a 32-year-old woman was in a life-threatening condition in hospital after being stabbed during the event.
Fifteen officers were assaulted, although none were seriously injured, and 90 arrests had been made on Sunday, police said.
A Section 60 order, allowing police to stop and search anyone in the specified area, was implemented from 6.05pm on Sunday evening until 2am on Monday morning, with the second day of the carnival expected to be heavily flanked by police officers.
A Metropolitan Police 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 safe as part of a very carefully planned policing operation.
“Regrettably, a minority came to commit crime and engage in violence.”
The main parade is held on Monday, described by organisers as the climax of the carnival with “party vibes”.
Around a million people are expected to attend over the bank holiday weekend with about 7,000 officers on duty across 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.
