The NATO force in Afghanistan said Monday that attacks by Afghan security personnel on their Western counterparts, while few in a number, have had a disproportionately large effect on troop morale.
NATO says 17 members of the international coalition have been killed in 10 attacks by their Afghan counterparts since January 1. A similar number of Afghan forces have also been killed by fellow Afghan soldiers or police.
The coalition also disputes Taliban claims of responsibility for the attacks.
Brigadier General Carsten Jacobson, coalition spokesman, says the number of attacks is actually quite low given that there are 130,000 NATO troops and 350,000 Afghan forces often training together in close quarters. But he says each incident has a disproportional effect, increasing mistrust between Afghan and international forces.
"Although the incidents are small in number we are aware on the gravity they have as an effect on morale," he said. "So therefore we are very carefully looking at every single incident."
Last week three coalition troops -- two British and one American -- were killed by Afghan security forces in different parts of the country. Also in Paktika province last week, Afghan officials said a member of an Afghan militia drugged his colleagues and killed at least nine of them as they slept.
The Afghan Taliban often takes credit for attacks by members of the Afghan security forces, but General Jacobson says in almost every insider attack, the perpetrator was not affiliated with the insurgency.
"Our findings are that the vast majority lie in the individual," he said. "Personal grievances are one of the major causes, plus a number of other cause including stress syndromes on soldiers who are living in a country that has been [enduring] 30 years of war."
NATO is putting a new emphasis on established procedures such as background checks for Afghan recruits, while implementing new security measures such as placing intelligence agents among troops during basic training, and assigning soldiers to guard their colleagues while they sleep.
Security has also been stepped up following the recent killing of 17 Afghan civilians, purportedly by a U.S. soldier, and the inadvertent burning of Qurans at an American military base. The incidents have increased tensions between Afghan officials and the international coalition at a time when cooperation is vital as foreign troops begin withdrawing ahead of a 2014 deadline.