A man wearing an Afghan security forces uniform has shot dead three NATO-led soldiers in the eastern part of the war-torn country, ISAF says.
So-called "insider attacks", in which Afghan forces turn their guns on their foreign 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.
In line with NATO policy, the statement did not give the victims' nationalities.
An Afghan official, speaking on condition of anonymity, said the incident happened during a training session in the insurgency-hit eastern province of Paktia.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
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 US 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.
There are 87,000 US-led forces fighting alongside about 350,000 Afghan security forces to repel a bloody Taliban insurgency which has been ongoing since 2001.
