Six Americans -- three soldiers and three civilians -- and an Afghan doctor were killed in two separate attacks in southern and eastern Afghanistan on Saturday.

According to the Associated Press, the attacks occurred the same day that U.S. Gen. Martin Dempsey, chairman of the Joint Chiefs of Staff, arrived in Afghanistan. Dempsey is visiting the country to evaluate how much training American soldiers can give Afghan security forces after the planned withdrawal of foreign troops in 2014.

Five of the American casualties occurred in the south, where a suicide bomber detonated a car filled with explosives, in what officials described as an assassination attempt targeting the governor of Zabul and his convoy. The explosion killed three U.S. service members, two American civilians, and the doctor, but not Gov. Mohammad Ashraf Nasery, who managed to escape the incident, the AP reported.

A sixth American -- a civilian -- was killed in eastern Afghanistan during an insurgent attack. The latest attacks bring the death count of foreign military forces killed in 2013 to 30, 22 of whom were Americans. Six foreign civilians have reportedly been killed in Afghanistan this year.