Thousands of police officers will be deployed among the Calypso dancers and steel drum bands at the Notting Hill Carnival following intelligence suggesting gangs want to create trouble there.
This year’s festival also will end early, before dark, as a precaution.
The force said Friday it has already arrested 40 people in raids ahead of the two-day event, which celebrates Caribbean culture and typically attracts about 1 million people.
Scotland Yard said there will be 5,500 officers on duty in London’s Notting Hill on Sunday and 6,500 on Monday, the main day of the carnival.
Thousands of officers will be on patrol elsewhere in the capital, creating a combined force that will dwarf the 5,000 officers who were on duty for the wedding of Prince William and Kate Middleton earlier this year.