"Guantanamo has become the gulag of our time," Amnesty Secretary General Irene Khan said as the London-based group launched its annual report. Amnesty International called for the camp to be closed.
The annual report accused the United States of shirking its responsibility to set the bar for human rights protections and said Washington has instead created a new lexicon for abuse and torture.
"Attempts to dilute the absolute ban on torture through new policies and quasi-management speak, such as 'environmental manipulation, stress positions and sensory manipulation,' was one of the most damaging assaults on global values."
Some 540 prisoners from about 40 countries are currently being held at the US prison camp in Guantanamo Bay, Cuba. More than 200 others have been released, though some are now jailed in their countries; many have been held for three years without charge.
The US government says it continues to be a leader in human rights, treating detainees humanely and investigating all claims of abuse, according to Navy Lt. Cmdr. Joe Carpenter, a spokesman for the Department of Defense. He had not seen the report and declined comment on it.
At least 10 cases of abuse or mistreatment have been documented and investigated at Guantanamo. There are several other cases that are pending.
"During the year, released detainees alleged that they had been tortured or ill-treated while in US custody in Afghanistan and Guantanamo. Evidence also emerged that others, including Federal Bureau of Investigation agents and the International Committee of the Red Cross, had found that such abuses had been committed against detainees," the report said.
The Geneva-based ICRC is the only independent group to have access to the Guantanamo detainees. Amnesty
"There's a myth going around that there's some kind of rule of law being applied," said Rob Freer, an Amnesty official who specializes in detention issues.
Amnesty acknowledged the human rights deficiencies came with a rash of terrorist actions, including the televised beheadings of captives in Iraq.
Still, the group said, governments forgot many victims in the fight against terrorism.
Khan singled out Sudan as one of the worst human rights violations of last year, saying that not only had the Sudanese government turned its back on its own people, but that the United Nations and Organization of African Unity acted too late to help.
She also said that the Organization of African Unity needed to do more about speaking out against human rights abuses in Africa, giving the example of Zimbabwe. She talked about human rights failures being compounded by big business's complicity.
Amnesty's report also pointed to Haiti, where human rights violators were allowed to regain positions of power after armed rebels and former soldiers ousted former President Jean-Bertrand Aristide last year.
Amnesty said in the Democratic Republic of Congo, there was no effective response to the systematic rape of tens of thousands of women and children, and in Afghanistan, a downward spiral of lawlessness and instability had shaken the country once again.
While criticizing the US detention mission at Guantanamo, Amnesty said one sign of hope was the US Supreme Court's decision in June that allowed prisoners to challenge the basis of their detention. It also said it was encouraging that Britain's high court lords ruled on the indefinite detention without charge or trial of "terrorist suspects."
"The challenge for the human rights movement is to harness the power of civil society and push governments to deliver on their human rights promises," said Khan.