A U.S. soldier killed last week in Afghanistan was stabbed in the neck by an Afghan teenager believed to be about 16 years old, U.S. officials confirmed Monday. The Pentagon had said in a statement last week that Sgt. Michael Cable died of injuries sustained when his unit came under attack by enemy forces. But unnamed U.S. officials told the Associated Press Cable had been playing with a group of Afghan children in an eastern province when the teenager stabbed him. Cable was one of 14 U.S. servicemembers killed in March, an uptick from the total of four in the previous two months.