The protesters accuse Sudan's president, Omar al-Bashir, of provoking a humanitarian crisis and blocking food and aid from entering the Nuba Mountains in the county's border region with South Sudan.

Clooney, his father, Nick and others, including Democratic U.S. Rep. Jim Moran of Virginia and NAACP President Ben Jealous, were arrested after being warned three times not to cross a police line outside the embassy. They were handcuffed and placed into a U.S. Secret Service van.

Clooney said earlier that he hopes to draw more attention to the issue and that if action is not taken in the next three to four months "we're going to have a real humanitarian disaster."