WASHINGTON — Anti-war groups today will kick off a first round of testimony describing alleged war crimes by American soldiers in Iraq and Afghanistan.

The 800-member organization, Iraq Veterans Against the War, says the event, called “Winter Soldier 2” and scheduled to run from March 13 through March 16 in Silver Spring, Md., is modeled on the 1971 anti-Vietnam War hearings named for the famous phrase of Thomas Paine in his 1776 pamphlet, “The Crisis.”

On January 31, 1971, Vietnam Veterans Against the War launched the first round of hearings that eventually launched the public career of John Kerry, who later that year testified before the Senate Foreign Relations Committee, where he said his fellow servicemen “razed villages in fashion reminiscent of Genghis Khan.”

The chairman of the Iraq Veterans Against the War, Camilo Mejia, said in a telephone interview yesterday that some 50 veterans would be testifying at the hearing, and that the group has collected written testimony from more than 100 former soldiers. The event will also feature testimony from Iraqi civilians.

Thus far, however, the reaction from Congress has not been as enthusiastic as it was a generation ago during the height of the Vietnam War. “I would not say we have received a whole lot of support from Congress,” Mr. Mejia said. He said that Rep. Jim McDermott, a Democrat of Washington State who has called for the impeachment of Vice President Cheney and President Bush, may attend but that the congressman’s attendance had not yet been confirmed.

Mr. Mejia, who served with the Florida National Guard in Jordan and Iraq in 2003, was demoted back to private when he was discharged and found by court martial to be guilty of desertion.

In the interview, Mr. Mejia said he did not participate in massacres, but he did say: “We did kill a lot of civilians. We tortured people.” In particular, Mr. Mejia said he participated in torture when he served as a guard at the Al-Asad Air Base. There, enemy combatants were held, and his unit, he said, would make sure to deprive them of sleep for 72 hours at a time. One method was by slamming a sledgehammer on a concrete wall next to the detainee’s head. He said: “We would also put guns to their heads and make them think they were about to be executed.”

Mr. Mejia also said he would talk about the “dehumanization of the enemy.” “You have to dehumanize the enemy. It is hard to say I am killing Mohammed, who is a schoolteacher with two children. You don’t call them human, you call them hajis which is a derogatory term we have, like gooks during Vietnam,” he said.

Mr. Mejia called the insurgent enemy in Iraq a “resistance” many times throughout the interview. He also said he did not consider the three national elections in Iraq in 2005 to be legitimate because of what he called the presence of an “occupation army.” He said he did not think the support of elected Iraqi leaders or U.N. resolutions mitigated the fact that the presence of American forces in Iraq constituted an “occupation.”

Mr. Mejia also drew a parallel between suicide bombers and the American Air Force. “When you drop a 500-pound bomb in a home, the bomb kills a lot of people,” Mr. Mejia said. “The difference between that and someone who straps explosives around their body is that that person has less resources.”

Iraq Veterans Against the War in the past has run into credibility problems. For example, the group promoted a man who claimed to be a former Army ranger, Jesse MacBeth, who was later found at least to be fabricating his military experiences. The group distanced itself from Mr. MacBeth and instituted what it says are stricter vetting procedures. The original “Winter Soldier” group faced similar challenges after the U.S. Army investigated many of the organization’s allegations in Vietnam and concluded many of the incidents could not be verified, according to a recently declassified report.

The executive director of the 20,000-member Vets for Freedom, a group that favors prolonged Iraqi engagement, Peter Hegseth, said yesterday that his organization would have a blogger and fellow veteran at the event to fact-check the claims made by the soldiers.

“These guys are admitting to individual war crimes,” he said. “If they committed or saw things that happened, they should have reported up the chain of command.” Mr. Hegseth, who himself served as a captain in the Army Reserve, said the opinions expressed at the event represented a “small minority of veterans.” He added: “This is not a widely held perspective in the military. It is unfortunate that those covering it are the international media. I keep asking what this does for America’s image in the world.”

“Most of this is intended to shock people,” he said. “They are about shocking audiences to get some media attention.”