Actor George Clooney and his father have been arrested at a protest outside the Sudanese Embassy in Washington.

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 country's border region with South Sudan.

Clooney, his father, Nick and others, including Democratic US Representative Jim Moran of Virginia and civil rights leader 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 US 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".