KHOST, Sept 21: A man wearing Afghan army uniform shot dead three US soldiers in the eastern part of the war-torn country, the Nato coalition said on Saturday.

So-called “insider attacks”, in which Afghan forces turn their guns on their international partners, have killed scores of foreign troops in Afghanistan, breeding fierce mistrust and threatening to derail the training of local forces to take over security duties ahead of Nato’s withdrawal next year.

“Three International Security Assistance Force (Isaf) service members died when an individual wearing an Afghan National Security Forces uniform shot them in eastern Afghanistan today,” an Isaf statement said, adding that both Isaf and Afghan officials were investigating the incident.

A US defence official confirmed that the three victims were from the United States. An Afghan official said the incident happened during a training session in the eastern province of Paktia.

An Afghan National Army (ANA) soldier opened fire on US soldiers in a military training camp, killing two on the spot, he said. A third later died of his wounds, he added.

The attacker was killed when Americans and Afghan soldiers returned fire, he said.

The threat of “insider attacks” has become so serious that foreign soldiers working with Afghan forces are regularly watched over by so-called “guardian angel” troops to provide protection from their supposed allies.

Isaf officials say that most insider attacks stem from personal grudges and cultural misunderstandings rather than Taliban plots.

Afghan soldiers and police are taking on responsibility for battling the Taliban militants from 87,000 US-led Nato combat troops who will leave by the end of 2014 — 13 years after a US-led invasion brought down the Taliban government.

But the US trained 350,000-strong Afghan security forces are suffering a steep rise in casualties as the Nato combat mission winds down and Afghan authorities try to bring stability ahead of the presidential poll set for April next year.—AFP