STERLING, Va. (AP) - A senior Pentagon official is apologizing to Washington-area Muslims for the burning of Qurans at a military base in Afghanistan. Peter Lavoy, acting assistant secretary of defense for Asia and Pacific security affairs, says the military is investigating and that all troops are being retrained in the handling of religious materials. Lavoy's remarks were Friday at a mosque in suburban Washington, D.C. They come after protests across Afghanistan over the burning of several Qurans at a U.S. military base. Military officials say 20 people have died in the protests, including two U.S. soldiers.