CAIRO - Human rights groups and former detainees in U.S. custody expressed disappointment Friday with the decision by President Barack Obama not to prosecute CIA operatives who used interrogation practices described by many as torture.

Obama sought to turn a page on what he called "a dark and painful chapter" with his announcement Thursday. He condemned the aggressive techniques -- including waterboarding, shackling and stripping -- used on terror suspects while promising not to legally pursue the perpetrators.

But the decision left some bitter in the Muslim world, where there was widespread anger over abuse of detained terror suspects. It could tarnish somewhat Obama's growing popularity among Arabs and Muslims, who have cheered his promises to close the Guantanamo Bay detention facilities and withdraw U.S. troops from Iraq.

"All of us in Guantanamo never had hope or faith in the American government," said Jomaa al-Dosari, a Saudi who spent six years in Guantanamo before being released last year.

"We only ask God for our rights and to demand justice for the wrongs we experience in this life," he said. "There will be a time in history when every person who committed a wrong will be punished."

The editor of the Saudi Arabia-based Arab News daily, Khaled Almaeena, said the decision not to prosecute "sends the wrong message."

"They destroyed people's lives ... Unfortunately, they're allowed to go scot free," he said of operatives who carried out the techniques.

The Obama administration Thursday released secret CIA memos detailing interrogation tactics sanctioned under the Bush administration.

As well as waterboarding, the memos authorized keeping detainees naked, in painful standing positions and in cold cells for long periods of time. Other techniques included depriving them of solid food and slapping them. Sleep deprivation, prolonged shackling and threats to a detainee's family also were used.

Obama's attorney general offered CIA operatives legal help if anyone else takes them to court, although the administration's offer of help did not extend to those outside the CIA who approved the so-called enhanced interrogation methods or any CIA officers who may have gone beyond what was allowed.

Many human rights groups condemned the decision, saying that it was necessary to have a full accounting of what took place.

"The release of CIA memos on interrogation methods by the U.S. Department of Justice appears to have offered a get-out-of-jail-free card to people involved in torture," Amnesty International said in a statement on its website. "Torture is never acceptable and those who conduct it should not escape justice."

In Egypt, Hafez Abu Saada, of the Egyptian Organization for Human Rights in Cairo, said the decision would encourage other countries to let abuses pass.

"Obama told us he will hold to account the people who committed a crime or a human rights violation," he said. "So this is a wrong signal to the perpetrators of human rights (abuses) -- especially third world countries -- and also a wrong signal to the international community."

Moazzam Begg, a British resident who spent more than two years in Guantanamo, said he wasn't surprised by the tactics revealed, saying "we witnessed" most of the techniques.

"It's the unwritten things, the things that happened in the heat of the moment on the battlefield -- like tying people up with chains and dragging them around -- that are worrying and will likely never come out," he said.

The International Commission of Jurists, a widely respected Geneva-based organization of legal experts from around the world, issued a scathing statement saying Obama should thoroughly investigate and prosecute officials who authorized and engaged in torture.

"Without holding to account the authors of a policy of torture and those executing it, there cannot be a return to the rule of law," said Wilder Tayler, acting secretary general of the ICJ.

Clara Gutteridge, a researcher with British human rights group Reprieve, which represents several Guantanamo inmates, said she was struck by the amount of time and effort apparently poured into drawing up the memos and justifying the use of what she called torture.

"It shows us the man-hours that have gone into this program, and making people believe that they are following the law," Gutteridge said.

In Islamabad, Pakistan, Saad Iqbal Madni, released from Guantanamo Bay last summer after seven years in detention, said sleep deprivation techniques were used on him. For months, he said, he was moved from cell to cell every two hours while shackled in an attempt to keep him awake.

"I believe that God will take care of anyone who did a wrong thing to me," said Madni.