The demonstrators 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.
"Immediately we need humanitarian aid to be allowed into the Sudan before it becomes the worst humanitarian crisis in the world, immediately. The second thing we are here to ask, it's a very simple thing, is for the government in Khartoum to stop randomly killing its own innocent men, women and children," Clooney said.
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.
"They were protesting the violence committed by the government of Sudan on its own innocent men, women and children. They were demanding they allow humanitarian aid into the country before it becomes the largest humanitarian crisis in the world," Clooney's publicist said in a statement shortly after the actor's arrest.
Earlier this week Clooney released an online video of a recent illegal trip he made to the war-torn country. The four-minute video highlights attacks on civilians in the Nuba Mountains, a region that U.S. officials say could soon suffer a severe hunger crisis.
Clooney also testified on Capitol Hill, urging senators to crack down on the people behind the Sudanese violence.
"Let's use the techniques we've learned from chasing terrorists and find and freeze the offshore bank accounts of these war criminals. They're not buying these weapons with Sudanese pounds. Let's work with the international community to toughen the sanctions, make Khartoum a very lonely place," Clooney said.
The Oscar-winning actor was released several hours later after paying a $100 fine. Adding a little levity to the situation, Clooney joked about his experience behind bars.
"It was really rough, you can imagine, have you ever been in a cell with these guys?" Clooney said.
Meantime, the Sudanese Embassy released a statement, saying Clooney "put on a show," and is misleading the American public on what's actually going on in Sudan.
"The actor put on quite the show that could possibly earn him yet another Golden Globe as he thoroughly played his role to perfection in a script that apparently ends in the lead actor's arrest. Only one problem, this matter is neither fiction nor set in Hollywood! The fictional lines he's parroting have real implications on innocent Sudanese who are now made all the more vulnerable to the massacres of the rebels," the statement read.
It goes on to say that Clooney has broken international law by sneaking into the border regions of Sudan without a visa, and the film he posted online is a skewed version of reality.
Clooney said he asked the president this week to involve China more in pushing for a solution in Sudan. He said international leaders need to "follow the money" flowing to Sudan's leaders to expose corruption. Clooney said he didn't know if his actions would make a difference, but that he at least wanted to make more people aware.
Check out photos of actor George Clooney and his father being arrested during a protest outside the Sudanese embassy in Washington, D.C.