Afghan National Army soldiers rushing to the scene moments after a car bomb exploded in front the PRT, Provincial Reconstruction Team, in Qalat, Zabul province, southern Afghanistan, Saturday, April 6, 2013. Six American troops and civilians and an Afghan doctor were killed in attacks on Saturday in southern and eastern Afghanistan, officials said. (AP Photo via AP video)

Photo by: APTN

Afghan National Army soldiers rushing to the scene moments after a car bomb exploded in front the PRT, Provincial Reconstruction Team, in Qalat, Zabul province, southern Afghanistan, Saturday, April 6, 2013. Six American troops and civilians and an Afghan doctor were killed in attacks on Saturday in southern and eastern Afghanistan, officials said. (AP Photo via AP video)