A legal-aid group that represents hundreds of Guantanamo Bay detainees condemned the U.S. military prison Tuesday as an "abomination" and called on Washington to close the facility, which opened five years ago this week.

Michael Ratner, president of the New York-based Center for Constitutional Rights, said reports of abuse inside Guantanamo and the prisoners' lack of access to the U.S. justice system damages America's international standing.

"The abomination that is Guantanamo Bay must be shut down," he said in a conference call with reporters. "There is simply no place in a democracy for offshore penal colonies in which people have no rights."

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To mark the five-year anniversary, demonstrations are planned Thursday in New York, London, Sydney, Australia, and other cities as well as dozens of small towns in the United States and Britain. A delegation including Cindy Sheehan, who became an anti-war activist after her soldier son was killed in Iraq, plans a protest in Cuba outside a gate leading to the U.S. Naval base.

The U.S. military says many of the "enemy combatants" imprisoned in the seaside compound ringed by razor wire and watchtowers provide interrogators with information about terror networks. The government has blocked their access to U.S. courts, claiming it has the authority to detain them indefinitely to keep America safe.

The first 20 detainees, shackled and blindfolded, arrived from Afghanistan to Guantanamo on Jan. 11, 2002. Several hundred have passed through the detention center on the U.S. Naval base in southeastern Cuba. About 395 foreign men are currently held there, detained because of alleged links to Al Qaeda or the Taliban.

But Ratner said 90 percent of the detainees never committed a hostile act against the United States. He described Guantanamo as "a legal failure."

In addition to protests planned for Thursday, many have urged the U.S. to close Guantanamo through an Internet campaign organized by Amnesty International. More than 6,000 of the brief clips of people speaking out against Guantanamo were listed on the YouTube Web site. The videos, only a few seconds in many cases, were shot in several languages.

Thursday's planned protests in towns across the United States have been organized by groups including Amnesty International, Witness Against Torture and Codepink.

"The overarching idea is peace will not be possible as long as people are still illegally held in the name of justice, in our name," said Dana Balickii, a spokeswoman for Codepink.

In Reykjavik, Iceland, demonstrators plan to release orange balloons to symbolize their hopes that detainees will be freed or receive fair trials. In London, hundreds of people dressed in orange jumpsuits, which are typically worn by detainees, plan to kneel for a photo opportunity mimicking the scenes of the first prisoners' arrival at Guantanamo.

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