Updated

An Italian soldier who was killed this week in western Afghanistan was shot by an Afghan soldier, not by insurgents as originally reported, NATO said Thursday.

Italy's defense minister said at the time that one Italian soldier was shot to death and another wounded Tuesday in Bala Murghab district of Badghis province. NATO called the incident an "insurgent attack."

On Thursday, the coalition issued a new statement correcting the account, saying that the two soldiers were cleaning their weapons at a combat outpost when an Afghan soldier approached them with an M16 rifle and asked to use their equipment to clean his gun.

The Italians saw that the Afghan soldier's rifle was loaded and asked him to unload it, at which point the Afghan soldier shot the two Italians and escaped from the base, NATO said.

Such turncoat shootings are uncommon among the Afghan forces fighting alongside coalition troops, but they have appeared to increase over the past year as both NATO and Afghan forces work more closely together. In some cases, such shootings have been a result of arguments that turned violent; in others, the Taliban has claimed that Afghan shooters were sleeper agents.

Last week, a Marine shot and killed an Afghan policeman after a dispute at a patrol base in southern Helmand province. In November, An Afghan border police officer opened fire on NATO troops during a training mission in Nangarhar province, killing six NATO service members before he was shot dead.

In the south, meanwhile, a roadside bomb killed three civilians — two men and one child — in Kandahar city, according to Zalmai Ayubi, a spokesman for the provincial government.

And in the north, NATO and Afghan forces killed more than 10 insurgents in two days of fighting, the alliance said.

The operation in Faryab province was aimed at disrupting Taliban cells that have moved freely in the area, the statement said. The troops searched many houses without incident but were fired on from some compounds and returned fire, the statement said.

Meanwhile, insurgent attacks killed three NATO service members — one in the north and two others in the south, the alliance said. It did not identify their nationalities or give further details.

It was not clear whether the NATO death in the north was related to the fighting in Faryab.

More than 20 NATO troops have been killed in Afghanistan so far this month — a bloody start to a year that NATO officials have said they expect to be particularly violent. NATO forces are pushing deeper into insurgent strongholds to try to undermine the strength of the Taliban enough to allow troops to start drawing down.