Gunman in Afghan security force uniform kills 3 NATO soldiers

An unidentified gunman wearing an Afghanistan security forces uniform shot dead three international soldiers in the nation's east, the NATO-led group said in a statement on Saturday.

"Three International Security Assistance Force service members died when an individual wearing an Afghan National Security Forces uniform shot them in eastern Afghanistan today," the NATO-led group said.

It's the first attack of this kind in recent months. Last year there was a surge in what is called green on blue attacks – the killing of United States soldiers by Afghanistan security forces.

The murders had undermined the trust and cooperation between Afghan and international forces in the country, causing observers of the war to wonder whether domestic forces could maintain security after international forces, specially the US, began to drawdown and eventually leave.

It's not clear if the gunman was only disguised as a member of Afghan security forces, or if he actually was a member.