A military official with knowledge of the incident told The Associated Press on Tuesday that it appeared the Qurans and other Islamic readings were being used to fuel extremism, and that detainees apparently were leaving notes for one another inside them.
The official, who did not want his nationality disclosed, spoke on condition of anonymity because he was not authorized to discuss the incident.
The top commander of U.S. and NATO forces in Afghanistan says the books were inadvertently given to troops for burning.
More than 2,000 angry Afghans protested outside an American air base on Tuesday after they learned that copies of the Quran, the Muslim holy book, were burned in a pile of garbage at a sprawling U.S. military base north of Kabul.
"Die, die, foreigners!" the demonstrators shouted. Some fired rifles into the air. Others threw rocks at the gate of the base and set tires ablaze.
The burning of the Quran and other religious books was unintentional, said U.S. Gen. John Allen, the top commander of American and NATO forces in Afghanistan.
The incident stoked anti-foreign sentiment that already is on the rise after a decade of war in Afghanistan and fueled the arguments of Afghans who claim foreign troops are not respectful of their culture or Islamic religion.
Text and Images: AP
Image: An Afghan protester gestures towards a US soldier in front of the US base of Bagram during an anti US demonstration in Bagram north of Kabul, Afghanistan on Tuesday.