KABUL, Afghanistan  — The U.S.-led coalition says an Afghan army soldier has killed two international service members in Afghanistan.

In a statement, the coalition says the Afghan soldier turned his weapon on coalition troops Saturday in western Afghanistan, killing two in the latest incident of so-called insider attacks.

Such attacks by members of the Afghan security forces against their colleagues or foreign troops threaten confidence in the Afghan forces as they work to take over responsibility from international troops.

The coalition did not disclose further details, but said the shooting was under investigation.

Earlier, NATO reported that five American service members were killed on Saturday by a roadside bomb in southern Afghanistan.