The fallout from the burning of Qurans at a U.S. base in Afghanistan has claimed the lives of two U.S. troops. An Afghan official tells CBS that an Afghan soldier shot the soldiers out of anger over the burning of the holy books. Protests over the incident have raged for three days in Afghanistan. Afghan police fired shots to disperse a mob of protesters who tried to break into a U.S. military base in eastern Afghanistan. President Obama has issued a formal apology for the handling of the Quran: "We will take the appropriate steps to avoid any recurrence, including holding accountable those responsible," he wrote in a letter to President Hamid Karzai.