About 280,000 attended the 2003 festival

The sixth Thames festival sees the Hungerford Bridge decorated with banners, a children's' Pleasure Garden and a firework display on the river.

On Sunday there will be a Night Carnival described by the organisers as the "UK's most exciting procession".

It takes place on Saturday and Sunday from 1200 BST to 2200 BST between Westminster and Southwark Bridges.

This year's festival sees a performance from Akito Kanto - 33 performers from Japan who balance 16-metre bamboo poles on foreheads and lower backs.

Clean water projects

And about 500 children from 45 primary schools in Camden, Hackney, Islington, Lambeth, Southwark, Tower Hamlets and Westminster are singing at the festival.

This year also sees the continuation of the Sing for Water project in which a performance of a mass choir raises money for clean WaterAid projects in Africa and India.

Initiated in 2002, by composer and songwriter Helen Chadwick, Sing for Water has so far raised over �57,000.

The mass choir is made of more than 450 people, representing 40 choirs.

There will also be a concert on a floating stage and people are being given the chance to get onto the Thames beach as well as many stalls and street performers.