A man wearing an Afghan army uniform opened fire on coalition troops in western Afghanistan, Nato officials said today.
Unconfirmed reports said the gunman died and several alliance soldiers were wounded in Saturday's attack .
A Nato statement said there were no fatalities among alliance soldiers in the shooting at an outpost in Bala Boluk district.
If the probe confirms that the gunman was a soldier, the shooting will 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.
Afghan Defence Ministry spokesman Gen Mohammad Zahir Azimi confirmed the attack and said Nato troops shot dead the gunman.
Coalition troops are to end their combat role in 2014, and the goal is to have 195,000 trained Afghan troops in service by next October. Afghan security forces have already started taking the lead in several regions as part of the process that will put them in charge of security across the nation by the end of 2014.
Commanders of Nato's training mission have said that coalition and Afghan forces keep a sharp eye out for possible Taliban infiltrators at the recruitment, training and deployment stages.
A Taliban statement today said that the insurgents were confident of victory and that the Nato forces would face the same fate as the Soviet invaders who withdrew from Afghanistan in 1989 after an almost decade-long war.
The insurgents "are successfully withstanding all the coalition forces led by the US invaders and will make them all face the same fate that befell the Red Army," said the statement marking the 32nd anniversary of the Soviet invasion in 1979.