An Afghan guard on Saturday shot dead two NATO troops accompanying a reconstruction team convoy traveling in a northern province, police said.
Police chief Gen. Mohammad Qasim Jangalbagh said the shooting took place in the Darah district of Panjshir province, about 62 miles north of the capital, Kabul.
Jangalbagh said the shooter was a bodyguard working for the country's second highest-ranking intelligence official.
He said the shooter stopped the convoy, engaged in an argument with NATO troops and opened fire.
Jangalbagh said another NATO soldier fired back and killed the shooter.
NATO said it was investigating the incident and declined to offer additional information.
An Afghan government official, who did not want to be named, told NBC News that the two NATO soldiers who were killed were Americans.
Panjshir is one of the areas that is about to be handed over to Afghan control in the coming weeks, NBC reported.