Five NATO troops were wounded after an Afghan soldier opened fire at a coalition base and then fled, officials revealed today. The attack occurred yesterday afternoon on a small base near a village in Wardak province, the New York Times reports. The wounded service members were all American, according to Afghan officials, though NATO has not identified them. Some 26 NATO troops have already been killed this year by Afghan police and soldiers, with three British soldiers killed earlier this week. Last year, 35 were killed. (More Afghanistan stories.)