NATO and Afghan authorities were investigating the shooting, which took place Saturday at an outpost in Bala Boluk district, about 340 miles (700 kilometers) west of Kabul, said Afghan Defense Ministry spokesman Gen. Mohammad Zahir Azimi.
A NATO statement said there were no fatalities among alliance soldiers, adding that it was its policy not to comment on other casualties. An official who asked not to be named because the investigation is ongoing said several coalition troops were wounded in the shooting. He said the man who opened fire was later killed by the NATO troops.
If the probe confirms the gunman was a soldier, the shooting would be the latest in a series of attacks by Afghans against coalition partners. Those shootings have raised fears of Taliban infiltration as NATO speeds up the training of Afghan security forces.