Protesters were reportedly heard shouting "die, foreigners, die!" after learning of the incident at Bagram Air Field. Some fired rifles into the air. Others threw rocks at the gate of the base and set tires ablaze.
A military official says Muslim holy books that were burned in a pile of garbage at the military base were removed from a library at a nearby detention center because they contained extremist messages or inscriptions.
A military official said 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 White House issued an apology Tuesday afternoon. Press secretary Jay Carney says it's a "deeply unfortunate incident" and doesn't reflect the respect the U.S. military has for the religious practices of the Afghan people.
Carney said an investigation was being undertaken to understand why it did happen and to ensure it didn't happen again.
The Associated Press contributed to this story.
