KABUL: An individual wearing an Afghan army uniform turned his weapon against foreign troops, killing one in southern Afghanistan in another apparent attack by Afghans against their foreign allies, the Nato command said Tuesday.

A statement said the incident, which occurred Monday, was under investigation and released no further details.

US officials in Washington, speaking on condition of anonymity because the details have not been formally released, confirmed that the victim was not an American.

Killings by uniformed Afghans of foreign soldiers and civilians rose dramatically last year, eroding confidence between the sides at a crucial turning point in the conflict. So-called insider attacks killed 61 personnel in 45 incidents last year compared to 35 killed in 21 attacks a year earlier, according to Nato.

This tally does not include the Dec 24 killing of an American civilian adviser by a female member of the Afghan police because an investigation of the reportedly mentally unstable woman is continuing.

In some cases, militants have donned Afghan army or police uniforms to attack foreign troops. And a number of attacks have also been carried out by members of Afghan security forces against their own comrades.

The attacks come as Nato and Afghan forces are in more intimate contact, with foreign troops handing over security to the Afghans and continuing to train them prior to an almost total withdrawal by the end of 2014.

The US will retain a residual force in Afghanistan past that date, the exact number of which is now being determined in Washington.