The theme for this year's carnival is "peace on the streets"

Youngsters paraded their costumes along the carnival route and played music on the Steel Pans as part of Children's Day.

Police said the mood of the crowd was "positive and good-humoured", but the numbers seemed to be down on last year.

Children of all ages and races danced and sang along the parade routes, which were lined with hundreds of stalls with a Caribbean theme.

The theme for this year's event, which continues on Monday, is "peace on the streets".

I think it is nice to see people from the Caribbean celebrating their own culture and being given space and opportunity to do so Jacqueline Laird In pics: carnival costumes

Richard Cornish from Stoke Newington who was there with Becky Saunders, Louis, seven, and Annie, five, told BBC News Online the sunny weather had put everyone in a good mood.

And Michael Burry, 29, from Streatham, who said he was forced to come by a friend from the US, said he was surprised by it.

"The atmosphere is better than expected, I expected it to be a bit unruly."

Police have been targeting suspected troublemakers in an attempt to make sure the carnival runs smoothly. There were 18 arrests confirmed by officers.

More than 1,000 stewards are helping the �5m Metropolitan Police operation, which uses 9,750 police officers.

'Gets bigger every year'

Another change for the event is that a company has been set-up to organise the carnival.

Professor Chris Mullard, the chairman of the London Notting Hill Carnival Ltd, told BBC London that people should "have a great day".

"It's a great, great experience. We are going to witness some of the greatest artistry that London has ever seen, the best costumes and the best gig in town."

The Notting Hill Carnival has become Europe's biggest street party.

Jacqueline Laird, who is in her early 40s, said she had been coming with her friend Margaret Blair since 1998.

"It is just about enjoying the celebration and it certainly gets bigger every year.

"I think it is nice to see people from the Caribbean celebrating their own culture and being given space and opportunity to do so."