A charity co-founded by George Clooney, Brad Pitt, Matt Damon and Don Cheadle has donated $500,000 (GBP250,000) to the United Nations World Food Program. The money, handed over by the stars' Not On Our Watch organisation, is earmarked for the U.N.'s food aid agency to prevent hunger in the troubled Darfur region of Sudan. In a statement, Clooney said: "Without immediate additional funding, humanitarian aid in the region will be crippled." Not On Our Watch has raised more than $9.3 million (GBP4.65 million) for Darfur, and last year (07) donated $1 million (GBP500,000) to the World Food Program. Clooney has become a leading celebrity advocate for action against the genocide in the Sudan after filming a documentary about the crisis last year (06).