Editor's note: Read this report in Arabic.
Kabul, Afghanistan (CNN) -- A NATO servicemember was shot to death by a gunman in an Afghan army uniform Sunday in southern Afghanistan, the allied command in Kabul reported.
The attacker was killed by coalition forces who returned fire, NATO's International Security Assistance Force reported. An investigation was under way, ISAF said, and no further details were immediately released.
In a separate attack, a roadside bomb struck a vehicle carrying U.S. troops in eastern Afghanistan, killing one American and wounding two, a Western official said. The bombing happened about 10 km (6 miles) south of an outpost in Paktia province, near the Pakistani border, the official said.
NATO's International Security Assistance Force initially reported three deaths from from an improvised explosive device Sunday, but later revised the toll to one. It did not identify the victim or nationality.
More than 1,900 Americans and another 1,000-plus allied troops have died in the 10-year-old conflict to date. The current year has seen a number of attacks on coalition forces by Afghan forces or by insurgents who have disguised themselves as Afghan troops, fueling distrust at a critical period of the conflict.