Four U.S. soldiers have been killed and one wounded in clashes with Taliban insurgents in Afghanistan, the U.S. military said on Thursday. More than 1,000 people have been killed in Afghanistan this year, the worst violence since the 2001 overthrow of the Taliban. The violence has surged as NATO prepares to takes over security duties from U.S.-led forces in the south, the rebel heartland. The latest clash occurred in the eastern province of Nuristan on Wednesday. Full Story