Hundreds of thousands of people have filled the streets of west London as the first day of the capital's Notting Hill Carnival got into full swing.
Sundays is children's day at the Notting Hill Carnival
Police said at least 300,000 people were on the streets for Sunday's Children's Day, for families, while organisers put the figure at 500,000.
Revellers were decked out in colourful costumes for the open-air party.
More than a million people are expected to visit the event throughout the bank holiday weekend.
A national steel band competition was held on Saturday evening in Kensal Green to warm up the area for carnival.
While Sunday's event tends to be quieter, with play areas for children, the big crowds flock to Monday's event, to dance to sound systems, watch the costumed Mas bands, steel bands and floats and enjoy the barbecues.
'All faiths and creeds'
Up to a million people are expected to attend the festival
Organiser Professor Chris Mullard said they hoped to capitalise on the sense of unity created by London's successful 2012 Olympic bid.
He said: "2012 showed what London is capable of when we show London as a city of the world, with all faiths and creeds uniting for a common goal. Nothing epitomises that better than carnival."
Officers made 49 arrests, although Notting Hill police stressed they were not all carnival-related. They included arrests for drugs, theft and drinking offences.
Mayor Ken Livingstone has organised a separate event in Hyde Park, the Caribbean Showcase - infuriating some organisers who say he is trying to undermine the carnival.
The mayor said the Hyde Park event would complement the carnival, and was particularly aimed at families with young children although there will be a live music stage.
He says the narrow streets are too cramped and dangerous for the carnival crowds - each year some residents leave for the weekend to escape the noise.
The annual event is one of London's most popular attractions
But many participants do not want carnival to be moved from what they see as its natural home.
The police have spent 12 months preparing for carnival and will use 11,000 police shifts to provide cover. Last year 183 people were arrested at the carnival.
Ch Insp Rod Charles said: "Given the thousands of people who flock to share in the spectacle of carnival, crime rates remain low. Our operation is aimed at making sure that crime levels stay that way."
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