Three US army rangers have been killed by an Afghan army solider who opened fire on them in eastern Afghanistan, an Afghan official said.
Afghan officials initially reported that two soldiers had been killed and two wounded but US officials later upgraded the deaht count.
Attahullah Khogyani, spokesman for the provincial governor in Nangarhar province, said the Afghan soldier was killed after the attack.
The Taliban claimed responsibility, with spokesman Zabiullah Mujahid saying one of their fighters had joined the Afghan army.
Such insider attacks have happened before in Afghanistan.
In March, another Afghan soldier was killed after he opened fire on foreign forces at a base in Helmand province, wounding three U.S. soldiers.