An Afghan police officer turned his gun on NATO troops at a remote checkpoint in the south of the country before dawn Sunday, killing four American troops, according to Afghan and international officials.
It was the third attack by Afghan forces or insurgents disguised in military uniforms against international forces in as many days, killing eight troops in all.
Recent months have seen a string of such insider attacks by Afghan forces against their international counterparts. The killings have imperiled the military partnership between Kabul and NATO, a working relationship that is key to the handover of security responsibilities to Afghan forces as international troops draw down.
Meanwhile, according to Afghan officials, airstrikes by NATO planes killed eight women and girls in another remote part of the country, fueling a long-standing grievance against a tactic used by international forces that Afghans say causes excessive civilian casualties.
The International Security Assistance Force, as the U.S.-led coalition is known, acknowledged that civilians had been killed and expressed its regret over the airstrike. It insisted known insurgents had been the target.
"ISAF takes full responsibility for this tragedy," a statement said.
Villagers from a remote part of Laghman province's Alingar district drove the bodies to the provincial capital, claiming they were killed by NATO aircraft while they were out gathering firewood before dawn.
"They were shouting 'Death to America!' They were condemning the attack," said Laghman provincial government spokesman Sarhadi Zewak.
