(CNN) — An Afghan soldier gunned down two NATO troops Monday in a so-called “green-on-blue” attack, according to the international coalition, the latest in a series of killings that has raised fears about the possible infiltration of the nation’s security forces.
The killings occurred the same day 10 Afghan soldiers were killed when members of their own unit opened fire on them at an army post in southern Helmand province, according to provincial officials.
The latest attacks come at a sensitive time for the United States and its NATO allies, who are preparing to withdraw the majority of their troops by 2014 under a plan that requires Afghan forces to take responsibility for the country’s security.
But Monday’s killings of two NATO service members raises to at least 42 troops killed in attacks by either Afghan forces or insurgents disguised as soldiers or police, according to coalition officials.
U.S. Marine Gen. John Allen, chief of the NATO-led International Security Assistance Force, said last week an estimated 25% percent of “green-on-blue” attacks are carried out by Taliban infiltrators.
The coalition did not provide details of the attack in eastern Afghanistan, saying only NATO “troops returned fire, killing the … soldier who committed the attack.”
Afghan and NATO officials were investigating the incident. The nationality of the two service members was not immediately released.
The term “green-on-blue” refers to a color coding system used by the military, in which blue refers to the friendly force, in this case the coalition; and green refers to an allied friendly forces, in this case Afghan security forces.
Afghan authorities are investigating the attack by five soldiers on their own unit in Helmand’s Washir district, which left 10 people dead and four wounded, Daud Ahmadi, a spokesman for Helmand’s provincial governor, said.
There has been no claim of responsibility for the killings, and the governor’s spokesman did not outline a possible motive in the attack.
The Taliban, meanwhile, was accused of beheading 17 people, including two women, in Helmand’s Shah Karez region north of Kandahar, the Interior Ministry said Monday.
The attack occurred Sunday, the ministry said. The provincial government, which confirmed the beheadings, stopped short of accusing the Taliban, saying officials were still investigating to determine who was responsible.
Neither the ministry nor the provincial governor provided details about a possible motive behind the attack.
CNN’s Chelsea J. Carter contributed to this report.
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