(CNN) -- Two investigations into the burning of Qurans by U.S. military personnel are complete, according to an International Security Assistance Force official.
Military personnel at Bagram Air Base in Afghanistan burned religious materials, including some Qurans, in February.
A joint investigation conducted by U.S. and Afghan authorities has been completed for several weeks, the official said. It is being reviewed by Gen. John Allen, the ISAF commander. A second investigation, conducted by the U.S. Army as a fact-finding review, is also complete. It is in the final stages of a legal review by the Army and is expected to be forwarded to Allen, the official said.
It is not clear what action Allen might take. He could decide to take no action, he could recommend criminal charges or he could administer so called "nonjudicial punishment," essentially written reprimands, the official said. It is also not clear if Allen will wait for the final Army report before making a decision.
Afghanistan erupted in violent protests in February when U.S. troops burned religious materials after they were removed from the detainee library at the Bagram prison. U.S. officials have said the destruction of religious materials was inadvertent and that books had been removed from the library because there were writings in them from detainees that officials believed were potentially extremist messages.
U.S. officials, including President Barack Obama, Defense Secretary Leon Panetta and Allen, expressed their regret for the incident. But it came on the heels of a video showing Marines urinating on Taliban bodies, and just a few weeks after the Quran incident, Staff Sgt Robert Bales went on a shooting rampage that killed 17 Afghan civilians. All those incidents have put strains on U.S.-Afghan military relations.