A special edition of American Idol is to raise funds for kids and young people in need in America and Africa.

The initiative, "Idol Gives Back", is a joint venture between Idol creator Simon Fuller and Richard Curtis, who developed Red Nose Day in the UK.

Contestants on the show will sing songs "about compassion and hope", while guest performers will include Josh Groban, Annie Lennox, Pink, Il Divo and Borat.

Viewers will vote for their favourite contestants as usual - but will also be encouraged to give donations to the cause. The show sponsors will also donate money for every vote cast.

"Richard approached me a couple of years ago and asked how we could work together to launch a major new televised charity initiative in the US," said Fuller. "After lengthy discussions it occurred to me that we should use American Idol as an existing platform to premiere this idea."

The special airs in the US on Tuesday, April 24 and Wednesday, April 25 and in the UK on Friday, April 27.