Newsweek magazine said in a recent edition investigators probing abuses at the U.S. military prison in Cuba had discovered that interrogators "had placed Korans on toilets, and in at least one case flushed a holy book down the toilet".

"American should apologise for this," said one student at the protest in Jalalabad city, about 130 km east of the Afghan capital, Kabul.

"Whoever has done this should be brought to justice and the Afghan government should condemn it."

Some protesters held up an effigy of U.S. President George W. Bush shouting "Death to Bush".

The students blocked the main road to Kabul but there were no clashes with police who kept watch from a distance, a witness said.

Politicians in neighbouring Pakistan have also called for an apology and an inquiry into the Newsweek report and assurances from Washington that those responsible would be punished.

Afghanistan's U.S.-backed president, Hamid Karzai, is due to visit the United States this month where he said he will seek special long-term ties with Washington.

The United States commands a foreign force in Afghanistan of about 18,300, most of them American, fighting Taliban insurgents and hunting Taliban and al Qaeda leaders, including Osama bin Laden, architect of the Sept. 11, 2001, attacks.

A high-level U.S. military investigation into accusations of detainee abuse at Guantanamo Bay has still to be completed and released.

The United States is holding more than 500 prisoners from its war on terrorism at the naval base on Cuba. Many of them were detained in Afghanistan after U.S.-led troops drove the Taliban from power in late 2001.