WASHINGTON, United States: After a diplomatic complaint from Pakistan, a key US ally in war on terror, the United States Defense Department is investigating a media report that interrogators at the American detention center at Guantanamo Bay, Cuba desecrated the Holy Quran.

The reported abuse of the Quran at the detention site has triggered a Pentagon inquiry and a vigorous condemnation by the US State Department, which says such activity would be reprehensible and contrary to Washington policy.

The US magazine Newsweek said in its latest edition that in order to rattle suspects, US interrogators placed copies of holy Quran on toilets and in at least one case "flushed a holy book down the toilet."

The Newsweek account spurred anti-US demonstrations in Pakistan and Afghanistan and a diplomatic complaint from the Pakistani government, which voicing deep concern to Washington demanded an apology from the US, an investigation and punishment for the perpetrators of what it termed a shameful act.

At a news briefing, acting State Department spokesman Thomas Casey said US officials agree the press report is troubling and merits investigation: "The allegations out there are certainly serious, and it would be important to have them be looked into. I know the US military, you can check with (them) on this, would treat any kinds of violations of religious rights of detainees very seriously. Obviously the destruction of any kind of holy book, whether it's a Bible or Quran, or any other document like that, is something that is reprehensible and not in keeping with US policies or practices," he said.

A senior official said later a Pentagon inquiry into the desecration charge had begun, though he provided no details.

A broader investigation of alleged abuse of detainees at Guantanamo has been under way for some time.

The Guantanamo facility was opened in 2002 as the central holding point for people captured in the US global war on terrorism. It still holds about 520 prisoners, many of them al-Qaida and Taleban suspects of various nationalities detained after the US-led invasion of Afghanistan.

On Tuesday, thousands of Afghan students took to the streets chanting “Death to America” and holding an effigy of the American President Bush top protest against desecration of the holy Quran.

“American should apologize for this,” said one student at the protest in Jalalabad city, about 130 km (80 miles) east of the Afghan capital, Kabul. “Whoever has done this should be brought to justice and the Afghan government should condemn it.”