4 troops slain in 2 separate attacks

Afghan soldier kills 1 with machine-gun fire; bomb claims other 3.

KABUL, Afghanistan — An Afghan soldier fatally shot an American service member and a local interpreter in southern Afghanistan, officials said Thursday, the latest in a string of attacks against U.S. and other foreign forces by their Afghan partners.

In the east, meanwhile, three U.S. service members were killed in a bomb attack, according to NATO and a U.S. official. The official confirmed the nationalities on condition of anonymity because the information had not yet been publicly released. Further details were not immediately available.

In the insider attack in southern Kandahar province, an Af- ghan soldier opened fire with a machine gun from atop a building, killing a U.S. soldier and an Afghan interpreter and wounding three other coalition service members before he was shot dead, a senior U.S. defense official said. The official spoke on condition of anonymity because he was not authorized to release details.

The U.S. military officially confirmed only that a man wearing an Afghan army uniform turned his gun on co- alition service members late Wednesday, killing one. The incident was under investigation, the military said.

Since the beginning of the year, there have been at least 16 such attacks against American and other foreign troops.

The U.S. military chooses its language carefully in describing insider shootings because of the possibility the assailants may be insurgents disguised in Afghan army uniforms and not actual members of the Afghan security forces. Such uniforms are easily available in markets in Afghanistan, and the Taliban have used them to mount previous attacks on foreign or Afghan military installations.

Since 2007, more than 80 NATO service members have been killed by Afghan security forces, according to an Associated Press tally, which is based on Pentagon figures released in February. More than 75 percent of the attacks have occurred in the past two years.