- Associated Press - Sunday, September 16, 2012

KABUL, Afghanistan — 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 U.S. 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 relationship that is key to the handover of security responsibilities to Afghan forces as international troops withdraw by the end of 2014.

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 (ISAF), 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.

NATO forces said the strike killed a large number of insurgents — as many as 45 — but also may have killed civilians.

There may have been five to eight Afghan civilians killed in the strike, said Capt. Dan Einert, a spokesman for international forces in Afghanistan. He said they were still investigating the report.

Afghan President Hamid Karzai “strongly condemns the airstrike by NATO forces which resulted in the deaths of eight women,” a statement from his office said. It said the Afghan government was also investigating.

The recent violence comes amid an international uproar about an Internet video mocking the Prophet Muhammad that many fear could further aggravate Afghan-U.S. relations. The video has sparked protests throughout the Muslim world, and the Afghan government blocked the YouTube site that hosts the video and its parent company, Google Inc., over the weekend in a move to prevent violent protests.

So far, protests in Afghanistan have remained peaceful.

Details of Sunday’s attack on the U.S. troops were slow to come out because it took place in a remote area, said Jamie Graybeal, another spokesman for the international military in Afghanistan.

“The attack took place in the vicinity of an outpost in southern Afghanistan. It is my understanding that it was a checkpoint,” Mr. Graybeal said.

International forces often work with Afghan police to man checkpoints as part of the effort to train and mentor the Afghan forces so that they can eventually operate on their own. The goal is to turn over all security responsibility for the country to the Afghans by the end of 2014, though numbers of NATO forces already have been reduced in many areas.

Mr. Graybeal said one police officer was killed in the clash with NATO troops but that the other officers at the site fled and it was unclear if they were involved in the attack or not.

Two NATO troops were wounded and were receiving treatment, Mr. Graybeal said. He did not say how serious the injuries were.

Afghan officials said the checkpoint in Zabul province’s Mizan district came under attack first from insurgents sometime around midnight. U.S. forces came to help the Afghan police respond to the attack, said Ghulam Gilani, the deputy police chief of the province.