Two U.S. soldiers were killed in eastern Afghanistan in an insurgent attack Saturday, news agencies reported citing U.S. military officials.

An official who spoke to the Associated Press on condition of anonymity said the two U.S. special operations forces were killed in insurgent fire in Wardak province, southwest of Kabul.

An Afghan policeman was killed and another was wounded when a bomb attached to a motorbike exploded in Sangin district of Helmand province in southern Afghanistan, AP reported citing provincial spokesman Ahmad Zarak.

Another Afghan policeman was killed in Kandahar city in a roadside bomb blast, provincial spokesman Ahmad Jawed Faisal was quoted saying by AP.

NATO-led missions in Afghanistan resumed earlier this week after they were “indefinitely” suspended Sept. 18, following a rise in the so-called “green-on-blue” attacks.

“Green-on-blue," is a color-coding system used by the military, in which blue signifies the friendly force and green represents allied forces, to indicate insider killings in the U.S. and NATO troops in Afghanistan.

The last of the 33,000 U.S. troops sent to Afghanistan nearly two years ago, to contain the Taliban insurgency, withdrew in September, even as the U.S. military deaths in the 11-year war hit the 2,000 mark.