NATO says a man wearing an Afghan army uniform shot dead a member of the NATO-led International Security Assistance Force (ISAF) in southern Afghanistan.
ISAF spokesman Hagen Messers said it has not yet been determined whether the attacker was a member of Afghanistan's security forces.
The attacker was shot and arrested after the attack.
ISAF would not reveal the nationality of the victim.
Mohammad Zarak, spokesman for the governor of Helmand Province, says the shooting took place in Nad Ali district after an argument between an Afghan soldier and coalition forces.
At least 57 members of ISAF have been killed in so-called "green-on-blue" attacks this year as NATO prepares to withdraw most combat troops by the end of 2014.
Based on reporting by AFP, dpa, and Reuters