KABUL, Afghanistan — An American service member was killed and two others were wounded in southern Afghanistan on Saturday in what officials described as an “apparent insider attack.”

The United States military, announcing the death in a statement, did not provide further details. The wounded service members were in stable condition, the military said. The name of the soldier who was killed was being withheld so the next of kin could be notified.

An American military officer familiar with the attack said it had occurred at a small base in Tarinkot, a town in Uruzgan Province, where roughly 150 soldiers who are stationed in Kandahar often rotate through to train Afghan soldiers. The outpost is one of several in the country where the Army’s Security Force Assistance Brigade is stationed. The unit — tasked with training and assisting the Afghan National Army — is one of the leading elements of the Trump administration’s new strategy in Afghanistan.

The death, the third American military fatality in Afghanistan this year, was a reminder that United States soldiers remain in the line of fire, although the war is now largely fought by Afghan security forces backed by American air power.