NATO says one NATO coalition soldier was killed in a firefight between Afghan and NATO troops in the eastern province of Nangarhar on April 8.
A NATO statement didn't reveal the dead soldier's nationality but Nangarhar police said the coalition soldiers involved in the incident were Americans.
Nangarhar police chief Fazel Ahmad Sherzad said an Afghan soldier opened fire on U.S. troops, causing casualties.
Sherzad said the attacker was shot dead and two Afghan soldiers were wounded.
Sherzad said the shooting took place after a meeting between provincial governors and a U.S. embassy official in the compound of Nangarhar's governor in the provincial capital, Jalalabad.
He said the Afghan soldier opened fire after the meeting ended and the U.S. official left the compound.
In January, an Afghan soldier killed three U.S. contractors in a similar insider attack.