A young female foreign service officer was among those killed in the blast Saturday in southern Afghanistan, US Secretary of State John Kerry said, DPA reported.
Four other State Department employees were injured, including one who was critically injured, Kerry said in a statement. Officials in Afghanistan said five people were killed, including three NATO soldiers and two civilian contractors, but did not mention a US diplomat.
The attack occurred as American officials and their Afghan colleagues were "on their way to donate books to students" in a school in Qalat, the provincial capital of Zabul province, Kerry said.
He said he had met the woman who was killed last week in Kabul, when she accompanied him during his visit to Afghanistan. "She tragically gave her young life working to give young Afghans the opportunity to have a better future," Kerry said.