3 NATO troops killed in Afghanistan

Someone wearing an Afghan National Army uniform shot at NATO soldiers Tuesday, killing three of them.

NATO's International Security Assistance Force said the shooting is now under investigation, according to CNN. There is said to have been a recent surge in insider attacks, also known as "green-on-blue" attacks, by Afghan security forces against US and other allied troops in Afghanistan. 

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This year alone, there are 34 insider attacks on record, reported the Associated Press. Forty-five mostly American coalition members have been killed, and at least a dozen of this year's attacks have occurred in the past month. The attacks have raised questions of a new Taliban strategy.

According to Voice of America, Tuesday's victims will be identified by their relevant national authorities.

A similar attack on Monday killed two ISAF troops when they were shot by another Afghan soldier, reported CNN. Other ISAF soldiers then shot and killed the gunman.

CNN also said that due to the recent surge in killings, US Gen. John Allen, ISAF's chief commander, ordered all allied forces at NATO headquarters in Kabul and other bases across Afghanistan earlier this month to carry loaded weapons at all times.