An explosion tore through a group of children gathered around foreign soldiers visiting a U.S.-funded road project, killing four kids and a policeman and wounding scores, including at least three American troops, AP quoted officials as saying. The Afghan Interior Ministry said in a statement that the blast Wednesday in Nangrahar province in Afghanistan"s east occurred when a passing police vehicle hit a mine. The ministry called it a terrorist act, implying the mine had been planted by insurgents. Adjman Pardes, chief of the province"s health department, said four children and a policeman died. He also told The Associated Press that 81 people, the vast majority of them schoolchildren, were wounded. Ahmad Zia Abdulzai, the spokesman for the provincial governor, told the AP earlier that the wounded included three U.S. soldiers. NATO"s International Security Assistance Force said nine of its soldiers were wounded, but could not specify their nationalities. Abdulzai said the soldiers were visiting a road construction project funded by the United States.