Foreign Service Officer Anne Smedinghoff of Pennsylvania had been assigned to the Kabul embassy since July and is believed to be the first U.S. diplomat to die in the line of duty since last year's terrorist attack on the consulate in Libya, CNN said.
Smedinghoff was killed along with eight other people when a car bomb went off as their convoy traveled along a road in Zabul province. The convoy also carried the provincial governor and a team of American military and civilian personnel.
Four other Americans perished and four State Department employees were injured.
The bombing occurred the same weekend the chairman of the U.S. Joint Chiefs of Staff, Gen. Martin Dempsey, made a surprise visit to Afghanistan.