"Two US soldiers and one ANA (Afghan National Army) soldier was wounded in the exchange," a US military statement said following the attack in Ghor province.

"Rogue elements of the 41st Afghan militia force division attacked an Afghan National Army convoy at approximately 2:30 pm (1000 GMT) today 45 kilometres (28 miles) north of Chagcharan," the statement said.

"They attacked with RPGs (rocket-propelled grenades) and small arms fire from vehicles traveling behind the convoy."

The wounded were evacuated to the military hospital at Bagram air base for treatment and they were in a stable condition, the statement said.

Afghan defence ministry spokesman General Mohammed Zahir Azimi had said earlier that "six people were injured, two or three of them American soldiers."

The convoy consisted of 18 ANA soldiers, seven US soldiers working as part of a training programme and two non-governmental organisation workers.

Ghor province has been the scene of frequent factional fighting between the Afghan army and local militias who are resisting a nationwide disarmament drive.

The United Nations pulled staff out of Ghor on July 15 after its election office was vandalised by an angry mob following a skirmish between the army and local militia commanders.

WAR.WIRE