A man in an Afghan army uniform turned his weapon on NATO troops and shot dead two service members on Thursday, the alliance said in what was the latest apparent attack by members of Afghan security forces against their coalition partners.
NATO said it was investigating the incident. It released no further details nor did it disclose the nationalities of the killed service members. It also did not say if the man in the Afghan uniform was killed or captured.
Meanwhile, a roadside bomb killed 10 police officers and wounded another in a restive district of southwestern Helmand province, which NATO had recently turned over, with much fanfare, to Afghan security control.
Taliban spokesman Qari Yousef Ahmadi claimed responsibility for the Helmand attack in a call to The Associated Press.
The explosion destroyed a police pickup truck as it drove through Zarghun Kalay village in Helmand's Nad Ali district, according to a spokesman for the provincial governor, Daud Ahmadi, and police chief Haji Abdul Marjan.
Both officials said the officers had left a training center and were headed home when their vehicle was blow up by insurgents. Marjan said they drove along the same road every day, while Ahmadi said eight of those killed were new recruits.
Nad Ali, which had been run by British troops, was one of the districts in Helmand that last month transitioned from NATO to Afghan security control.
The handover was the second step in a transition that President Hamid Karzai hopes will leave Afghan forces in control of the entire country by the end of 2014, when the U.S.-led coalition's combat mission is scheduled to end.
However, shootings such as the one in the east _ where the attackers are either Afghan soldiers who turn on NATO troops, or reported insurgents dressed in Afghan uniforms _ have raised fears of increased Taliban infiltration of the Afghan police and army as NATO speeds up the training of the security forces.
Last week, an Afghan soldier opened fire on coalition troops inside an outpost in western Herat province, wounding a number of alliance troops. The attacker was killed in the incident.
NATO's training mission hopes have about 350,000 troops trained and ready by the end of 2014.
Eastern Afghanistan has become the focus of coalition efforts against insurgents, who infiltrate into Afghanistan across the rugged frontier from safe havens in neighboring Pakistan. The U.S. and its allies have asked Pakistan to crack down on the safe haves in that country's lawless tribal areas, but relations between the two militaries have reached rock bottom following a NATO cross-border attack that killed 24 Pakistani soldiers last month.
The two NATO deaths bring December's toll of foreign troops killed in Afghanistan to 25, for a total of 541 so far this year.
On Tuesday, three NATO troops were killed by a roadside bomb in eastern Afghanistan. An alliance statement provided no further details, but the Taliban claimed the victims were U.S. soldiers who were riding in a military convoy when a roadside bomb exploded next to their vehicle. There was no independent confirmation of the claim.
The yearly total is considerably lower than for 2010, when more than 700 troops died. The number of wounded has remained high, dipping only slightly from last year's total of more than 5,000 service members.
Associated Press Writer Mirwais Khan contributed to this story from Kandahar, Afghanistan.