Afghanistan blast kills at least 2 NATO troops At least two Western troops were killed Wednesday by an explosion in northern Afghanistan, and a provincial police chief in the northwest of the country tells CBS News that it was a suicide attack on U.S. soldiers which actually left four Americans dead. A suicide bomber killed the four U.S. troops, along with four Afghan police officers and several civilians, in an attack at a park in the northwestern province of Faryab, according to the provincial police chief. NATO convoy attacked in deadly Afghan ambush 11 suicide vests found at Afghan military HQ Afghan troops turn guns on NATO allies, killing 3 The U.S. military has not confirmed the American deaths. NATO said in a written statement that two service members had been killed in northern Afghanistan by an improvised explosive device, but the discrepancies in the information from NATO and the Afghan police chief could not be immediately reconciled. NATO did not give the nationalities of the troops slain, or any further details on where or how they were killed.