KABUL, Afghanistan (AP) - A military official says Muslim holy books that were burned in a pile of garbage at a U.S. military base in Afghanistan had been removed from a library at a nearby detention center because they contained extremist messages or inscriptions.

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.