By Ismail Sameem
KANDAHAR (Reuters) - An elite Afghan soldier shot dead an American mentor and his translator at a U.S. base, Afghan officials said on Friday, in the first rogue shooting blamed on the country's new and closely vetted special forces.
The soldier opened fire at an American military base on Wednesday in Shah Wali Kot district, in volatile Kandahar province, said General Abdul Hamid, the commander of Afghan army forces in the Taliban's southern heartland.
"The shooting took place after a verbal conflict where the Afghan special forces soldier opened fire and killed an American special forces member and his translator," Hamid told Reuters.
At least 16 western soldiers have been killed this year in so-called green on blue shootings, which are an increasing worry for both NATO and Afghan commanders, eroding trust on both sides as Western combat troops look to leave the country in 2014.
The latest shooting will be of grave concern to both sides, at it is the first involving a member of Afghanistan's new special forces, which undergo rigorous vetting as part of their selection into the country's top anti-insurgent force.
NATO's top general in the country, U.S. Marine General John Allen, and Afghan Defence Minister General Abdul Rahim Wardak only this month signed an agreement for Afghan special troops to spearhead controversial night raids on Afghan homes, which are seen as one of the most potent anti-insurgent tactics.
Qari Yousef Ahmadi, a spokesman for the Afghan Taliban, claimed responsibility for the attack in a phone text message sent to journalists, saying the Afghan soldier was "an insurgent infiltrator called Zakerullah".
The claim could not immediately be corroborated, and the Taliban frequently claim responsibility for attacks by disgruntled Afghan soldiers.
Hamid said U.S. soldiers had immediately fired back and killed the gunman, as well as another Afghan special forces soldiers who was caught up in the ensuing crossfire.
Green on blue shootings have severely strained U.S.-Afghan ties as both allies look to lock-in a security agreement to be signed at a NATO meeting in late May, covering a U.S. presence in Afghanistan for a decade beyond the 2014 pullout.
But NATO commanders argue the growing number of shootings is in proportion to the growing size of Afghan security forces towards an eventual 352,000 target.
"When we analyze the problem, it occurs for a number of reasons, and not as many as you would expect show any evidence of insurgent initiation, or insurgent backing," a senior NATO official who could not be identified said last week.
"Quite often people resolve their personal problems by resorting to the use of a weapon. It's more of a cultural thing here."
(Writing by Rob Taylor; Editing by Nick Macfie)