Afghan soldier killed U.S. trainers after row: ministry

KABUL (Reuters) - The killing of two U.S. civilian trainers by an Afghan soldier at a base in northern Afghanistan was the result of a "verbal argument," the Afghan Defense Ministry said Wednesday.

Tuesday, the NATO-led force said two U.S. civilians and an Afghan soldier had been killed in a shooting by another Afghan soldier, possibly an officer, but could not say whether the deaths were an accident or had been intentional.

The shooting happened Tuesday after an argument broke out between an Afghan soldier and U.S. instructors at a training center on an Afghan army base in northern Balkh province, the defense ministry said.

"As a result, two U.S. trainers were killed and one more was wounded," it said, adding the shooter and another Afghan soldier were then killed by return fire.

U.S. embassy spokeswoman Caitlin Hayden confirmed two U.S. citizens had been killed in a shooting incident, but could not release any more details.

A spokesman for the NATO-led force said they were still conducting an investigation with the Afghan Defense Ministry and could not still confirm whether the shooting had resulted from an argument.

The first announcement of the shooting came just as foreign dignitaries and ministers were wrapping up an international conference in Kabul Tuesday, where delegates backed a government plan for Afghan troops to take the lead in securing the whole country by the end of 2014.

The conference also agreed to announce the start of security transition to Afghans in some areas of the country by the end of this year, but many say those deadlines are too ambitious.

Incidents such as Tuesday's shooting can only cast further doubt over the capability and reliability of the Afghan security forces as Western nations seek to hand over responsibility in a bid to withdraw from an increasingly unpopular war.

The shooting was only the latest in a series of similar attacks in recent years highlighting the sometimes testy relations between Afghan troops and their foreign trainers.

Less than two weeks ago, a renegade Afghan trooper gunned down three British soldiers, including two officers, in what was said to be a premeditated attack in the volatile southern province of Helmand.

In November, an Afghan policeman killed five British soldiers at a military compound in southern Helmand province. The Taliban said he was one of their fighters who had infiltrated the force and the incident prompted Britain to look at its vetting procedure for Afghan police.

Four U.S. troops were killed and three were wounded by Afghan soldiers in two other incidents last year, one in the northeast and one just south of Kabul.

The spokesman for NATO-led forces, Lieutenant Colonel Goetz Haffke said he could say yet whether the latest shooting signified a new trend or not.

(Writing by Jonathon Burch; Editing by David Fox)