Secretary of State Condoleezza Rice, in an interview, brushed off growing calls for an independent investigation of conditions at the Guantanamo Bay detention center and labeled as "absurd" a new Amnesty International report equating the facility with Soviet-era gulags.

She said an outside investigation of the facility at the U.S. naval base in Cuba was not necessary.

"The United States is as open a society as you will find," she said, and the administration is being held accountable "by a free press, by a Congress that is a separate and coequal branch of government, and by its own expectations of what is right."

Pakistani President Pervez Musharraf, a close Bush ally, last week demanded an investigation of allegations that U.S. interrogators abused the Koran, the Muslim holy book, at Guantanamo Bay. The Pentagon is investigating five instances when the Koran may have been mishandled, but officials say they have found no evidence to support the incendiary charge that U.S. personnel flushed the holy book down a toilet.

Another U.S. ally, Afghan President Hamid Karzai, expressed anger over new reports of how detainees had died while American forces were interrogating them in Afghanistan.

Amnesty's report also said that despite "near-universal outrage" over treatment of detainees, "neither the U.S. administration nor the U.S. Congress has called for a full and independent investigation."

Rice, a Soviet scholar by training, seemed particularly indignant at Amnesty's characterization of Guantanamo Bay as "the gulag of our times," an allusion to Soviet prison camps under Joseph Stalin.

While the human-rights group has done important work around the world, "this is unfortunate and sad," she said. At another point in the interview, she said: "I think it's absurd language."

"The United States of America is one of the strongest defenders of human rights around the world. We've fought hard and worked hard even in the circumstances of a new kind of war [on terrorism] to treat people humanely," Rice said.

While acknowledging that "sometimes bad things happen," Rice argued that the charges of Koran abuse and other violations should be put in context.

American personnel at Guantanamo Bay have shown great respect for detainees' religion, for example providing them with prayer mats and arrows pointing to Mecca, the direction that Muslims turn to pray, she said.

She also expressed concern that American forces would be tarred unfairly by the actions of a few.

"A lot of the men and women in uniform, who people sometimes by association look at in the context of [abuses at the Iraqi prison] Abu Ghraib, have liberated 50 million people by their own blood and sacrifice over the last 31/2 years," she said.

Rice spoke late Thursday as she flew across the country from Washington in a small jet to take a rare vacation in California.

She gave a speech Friday in San Francisco at the Commonwealth Club of California, outlining Bush's second-term campaign to expand democracy around the world.

She was interrupted when two audience members, clad in black hoods and capes reminiscent of the photographs of detainees at Abu Ghraib, stood in silent protest. They and two others were thrown out of San Francisco's Davies Symphony Hall, chanting, "Stop the torture. Stop the killing. U.S. out of Iraq."

Rice attempted to turn the interruption to her advantage. Freedom is coming to Iraq, Afghanistan, Lebanon, and other Muslim societies, she said, and the audience applauded.

"They, too, will be able to speak their minds," Rice said. "What a wonderful thing democracy is."

In the interview, Rice, who had just come from Bush's White House meeting with Palestinian leader Mahmoud Abbas, indicated that she was intensely focused on Israel's planned withdrawal from the Gaza Strip.

The withdrawal is a huge opportunity for the Palestinians to begin building their own state, the secretary of state said. But she also expressed worry about how much Abbas and others had to accomplish before the scheduled beginning of Israel's disengagement in August.

"When we talk about a successful withdrawal from Gaza, we obviously mean that the Israelis are able to leave in conditions that are peaceful," she said. "But we also mean that the Palestinians are left with governing structures... that then become the foundation for a broader Palestinian state.

"It's a lot to try and do in several months, but everybody seems very dedicated."