US soldier 'stabbed to death by Afghan teen'

The Pentagon had initially given a different version of events

The body of Sgt Michael Cable, 26, returning home from Afghanistan (AP)

An Afghan teenager has killed an American soldier by running up from behind and stabbing him in the neck, according to officials.

In a statement last week, The Pentagon said that Sgt Michael Cable, a 26-year-old from Philpot, Kentucky, died from injuries sustained when his unit was attacked by enemy forces.

But according to an updated account, Sgt. Cable was guarding a meeting of Afghan and US officials near the border with Pakistan last Wednesday. Soldiers believed they had secured the area beforehand.

The incident took place in Shinwar district in Afghanistan's eastern Nangarhar province. New recruits to Afghan Local Police (ALP), which is backed by the Afghanistan military, were being sworn in nearby.

Sgt Cable is said to have been playing with a group of children when the attacker, thought to be around 16-years-old, ran up and stabbed him in the neck with a large knife. The attacker then fled over the border to Pakistan.

The killing comes as the number of US soldiers killed in Afghanistan in March rose to 14, almost double the number killed in January and February combined, according to Associated Press.

The sharp increase is believed to due to the start of the spring fighting season when the Taliban and other insurgents take advantage of improved weather to step up attacks.

Taliban spokesman Zabiullah Mujahid named the attacker as a 16-year-old named Khalid. He said the young man was acting independently when he killed the soldier but had since joined the Islamic militant movement.

A district official Zalmai Khan did not provide a name or confirm the Taliban's claim.

Cable's brother Raymond Johnston, 42, said the Army told the family the basics of what happened and that his brother was stabbed in the neck from behind.

Johnston said his brother, who also did a tour of duty in Iraq, was "prepared before he left for anything that happened" in Afghanistan.

Cable met individually with Johnston and three other family members before leaving for Afghanistan and had similar conversations with each - that the deployment was extremely hazardous and that his family and friends should "continue to enjoy life" if he was killed.

"He was able to communicate to the family about if the worst was supposed to happen, what we were supposed to do," Johnston said.