Kabul, Afghanistan (CNN) -- Two foreign troops who went missing Friday in Afghanistan are Americans who have been abducted, an Afghan intelligence source told CNN Saturday.

NATO's International Security Assistance Force and two U.S. military officials confirmed that the two missing service members are American. NATO said they went missing after leaving their compound in Kabul city Friday afternoon and did not return.

Forces have launched a search for the service members and the military vehicle they were in, ISAF said.

Their duty status is "whereabouts unknown," the U.S. officials said.

The intelligence source told CNN that the two were abducted in Logar province, south of Kabul -- Afghanistan's capital.

The development comes as five U.S. soldiers were killed in bombings in southern Afghanistan on Saturday.

CNN's Atia Abawi and Barbara Starr contributed to this report.