KABUL, Afghanistan – An attacker wearing an Afghan army uniform opened fire on NATO troops Friday in the country's east, killing one service member, the coalition said.
The Taliban claimed responsibility for the attack, which an Afghan defense official said took place in Kunar province. The official spoke on condition of anonymity because he was not authorized to speak to the media.
It was the 20th attack this year in which Afghan soldiers or insurgents disguised in military uniforms have turned their weapons on foreign troops. The incidents have raised the level of mistrust between the U.S.-led coalition and their Afghan partners and raised questions about the readiness of local forces to take over from NATO ahead of a 2014 deadline for the withdrawal of foreign combat troops.
The NATO statement provided no details about Friday's attack and did not give the nationality of the service member killed. NATO usually waits for member nations to provide details about troop deaths.
The coalition said an investigation was under way.
In a statement, Taliban spokesman Zabiullah Mujahid claimed the insurgent group was behind the attack. The Taliban regularly take credit for attacks in the country, even if they were not involved.
The insider threat in which Afghan soldiers or militants disguised in uniforms turn on NATO troops has existed for years but has grown more deadly. The 20 insider attacks so far this year have killed 13 soldiers, compared to 21 attacks last year that killed 35 coalition service members, according to a NATO tally.
That compares with 11 fatal attacks and 20 deaths in 2010. And in 2007 and 2008 there were a combined total of four attacks and four deaths.
The U.S.-led coalition routinely reports each time an American or other foreign soldier is killed by an Afghan in uniform, but the military is underreporting the number of overall attacks. The Associated Press reported last month that the coalition does not report attacks in which an Afghan wounds — or misses — his U.S. or allied target. It also doesn't report the wounding of troops who were attacked alongside those who were killed.
U.S. officials say that in most cases the rogue soldiers are motivated not by sympathy for the Taliban or on orders from the insurgents, but rather act as a result of personal grievances against the coalition.