An Afghan soldier shot three U.S. troops at a base in the country on Sunday, officials said. The three Americans were wounded, while the assailant was shot dead. U.S. Navy Capt. Bill Salvin said the Afghan soldier was killed “to end the attack,” suggesting it was an insider attack on American troops. An Afghan army spokesman, however, said the shots rang out accidentally. So-called insider attacks have resulted in the deaths of several Americans in Afghanistan.