A human rights group demanded that Washington investigate reports the United States tortured prisoners at secret detention facilities overseas, including one in Afghanistan, allegations that the U.S. military denied Saturday.

"U.S. officials who take part in torture, authorize it, or even close their eyes to it, can be prosecuted by courts anywhere in the world," the New York-based Human Rights Watch said in a statement Friday.

At Bagram Air Base in Afghanistan, where some of the abuse allegedly occurred, a U.S. military spokesman denied the allegations. He said prisoners held at a detention facility off-limits to the press are allowed to meet with representatives of the international Red Cross every week.

"The accusation of inhumane treatment is something that I can clearly refute. The things that they talked about, the inhumane conditions ... are things that do not go on here," Maj. Steve Clutter said Saturday, referring to a Washington Post article published earlier in the week.

The Post article quoted anonymous intelligence officials as saying suspected Al Qaeda and Taliban prisoners had been subjected to so-called "stress and duress" techniques at CIA facilities at Bagram and at the Indian Ocean island of Diego Garcia, a British territory.

The report said the techniques included forcing inmates to stand or kneel for hours in black hoods or spray-painted goggles, holding them in "awkward, painful positions," and depriving them of medical care or sleep with a "24-hour bombardment of lights."

"Such acts, if true, violate international legal prohibitions against torture and other ill-treatment under treaties that the United States has ratified," Human Rights Watch said.

About 100 lower-level prisoners who didn't cooperate with interrogators were handed over to allied nations, including Jordan, Egypt and Morocco. Those countries' intelligence services are allegedly known for brutality and may beat prisoners to get information the CIA wants, the Washington Post said.

Human Rights Watch said President Bush's administration "must promptly investigate and address allegations of torture of suspected Al Qaeda detainees or risk criminal prosecution."

"Such acts are "grave breaches," or war crimes, under the 1949 Geneva Conventions," Human Rights Watch said.

The Washington Post described the secret detention facility at Bagram, a sprawling base that is headquarters to U.S. and coalition troops in Afghanistan, as a group of metal shipping containers surrounded by concertina wire.

Clutter said he was not aware of any CIA detention facility on the base, but said about 60 prisoners were held at another off-limits detention center at Bagram -- a large concrete building surrounded by barbed wire that journalists are prohibited from visiting.

The Washington Post said U.S. military police or U.S. Special Forces troops have beaten captured suspects and said "alleged terrorists are commonly blindfolded and thrown into walls, bound in painful positions, subjected to loud noises and deprived of sleep."

Clutter said delegates from the International Committee of the Red Cross visited the 60 or so prisoners at Bagram every week. He said prisoners had full access to medical care, were fed hot meals three times a day, and were given heat during the winter.

The Post article described its anonymous sources as "several former intelligence officials and 10 current U.S. national security officials -- including several people who witnessed the handling of prisoners." It said national security officials interviewed "defended the use of violence against captives as just and necessary."

U.S. Army investigators are looking into the deaths of two Afghan prisoners who died in U.S. custody at Bagram earlier this month. Initial autopsies performed by coalition medical teams found that one inmate died of a pulmonary embolism and the second died of a heart attack, the U.S. military has said.