Updated

An Afghan soldier opened fire Thursday on his NATO trainers, killing one American and wounding several other coalition troops in the country's east, officials said.

Attacks in which Afghan forces turn their guns on their international partners have killed scores of US-led troops, breeding mistrust and undermining efforts to train local forces before NATO combat troops withdraw next year.

The latest shooting was at a military training facility and base in the eastern province of Paktia, known to be one of the hotbeds of the Taliban insurgency, an Afghan official said.

A US defense official, speaking on condition of anonymity, said the NATO trainer killed was an American.

The soldier attached to NATO's International Security Assistance Force (ISAF) was inside the base when attacked, Rohullah Samoon, the local administration spokesman, told AFP from the provincial capital Gadez.

ISAF said the attacker, described as "wearing Afghan national security forces uniform", was killed in return fire from other troops on the ground.

ISAF did not provide further details including the exact location of the incident.

Attacks of this nature, locally known as "insider" or "green on blue" are common in Afghanistan where Afghan troops, some of them reportedly affiliated to insurgent groups, turn on NATO and US allies.

An Afghan soldier shot dead three US soldiers during a training exercise in Paktia last Saturday.