The convoy was near a hospital and a NATO base at the time of the explosion. Five Afghans, including a student and two reporters, were wounded, a local official said.
The attack came as the top U.S. general, Martin Dempsey, chairman of the Joint Chiefs of Staff, arrived in the country for a short visit to assess how much training Afghan troops need before U.S. troops pull out as planned by the end of 2014.
In an attack in Afghanistan’s east, an American civilian working with the U.S. government was killed during an insurgent attack, the NATO-led International Security Assistance Force said in a statement.