Two U.S. soldiers have been killed and four others wounded when men in Afghan army uniforms turned their weapons on American forces in eastern Afghanistan.
The shooting Wednesday took place in Kapisa province, just north of the capital, Kabul.
The frequency of these insider attacks has declined markedly in recent months.
At the height of the problem, in 2012, U.S. and coalition troops were more often fighting and training alongside their Afghan partners; the relationship evolved last year with the Afghans taking a lead combat role. That has put the Americans and other coalition troops in a less visible position as advisers.