"Detainees, halt!" yelled Carmen Trotta, a volunteer with the group Witness Against Torture, who wore military fatigues as he gathered the protesters in Lafayette Park. "Turn left. Face the home of your captor."

The rally and street theater were organized by a coalition of groups - including Amnesty International, the Center for Constitutional Rights and September 11 Families for Peaceful Tomorrows - that are calling on the administration to either try Guantanamo Bay detainees in federal court or release them.

"We believe in and promote the rule of law," said Valerie Lucznikowska, whose nephew was killed in the Sept. 11, 2001, attacks on the World Trade Center and who described the military detention center in Cuba as a "living stain on America."

There was little sympathy among the protesters toward President Obama for insisting that he remains committed to closing the prison but has been frustrated at every turn by political opposition on Capitol Hill. Congress has barred the administration from using Defense Department money in 2011 to transfer any detainee to the United States for any purpose.

Obama's "the guy with the bully pulpit and he hasn't made the argument," said Tom Parker, policy director for terrorism, counterterrorism and human rights at Amnesty International. "His comments on Guantanamo have been sparing. And there needs to be a great deal more done at the political level."

Speakers at the rally criticized the administration for not proceeding with federal trials, countenancing a formal system of indefinite detention and not repatriating nearly 60 Yemenis who were cleared to go home by the administration's own inter-agency task force.

The president placed a moratorium on the transfer of any Yemenis following an attempt to bring down a plane over Detroit on Christmas Day 2009. Umar Farouk Abdulmutallab, a Nigerian accused of trying to detonate a bomb on the aircraft, was trained by an al-Qaeda affiliate in Yemen. And administration officials have expressed concern about the country's ability to monitor any returned detainees.

But activists said the administration is pursuing a policy of collective "guilt by nationality," as Andy Worthington, a British author who spoke at the rally, put it.

From the White House, the protesters marched to the Justice Department, where they held a silent vigil.

"We are here with heavy hearts but fierce determination," said Frida Berrigan of Witness Against Torture. "If Guantanamo does not close now, we fear it will never close."