Two American soldiers in Afghanistan were killed Monday along with several local troops in the latest suspected insider attack on the international military force, the US military said.
Afghan officials said the incident took place in Wardak, a flashpoint province for Taliban violence on the doorstep of Kabul, where Afghan President Hamid Karzai last month demanded US special forces to leave, AFP reported.
"Two US Forces-Afghanistan service members died in eastern Afghanistan today when an individual wearing an Afghan National Security Forces uniform turned a weapon on US and Afghan forces," the US force in Afghanistan said in a statement.
A spokesman for NATO's International Security Assistance Force (ISAF) told AFP that several Afghan soldiers were also killed.
Interior ministry spokesman Sediq Sediqqi confirmed the location as Jalrez in Wardak and said a delegation had been sent from Kabul to investigate.
The incident comes after the end of a two-week ultimatum by Karzai to remove a US-operated elite force from the troubled province where the Afghan leader said they were fuelling "insecurity and instability".
NATO soldiers are fighting alongside Afghan colleagues to thwart Taliban militants, but more than 60 foreign soldiers were killed in 2012 in "insider attacks" that have bred mistrust and threatened to derail the training process.
The last such attack, known as "green on blue" in military jargon, came on Friday in the restive eastern province of Kapisa where a NATO civilian contractor was killed by three people wearing Afghan security force uniforms.
The Taliban, leading an 11-year insurgency against Karzai's Western-backed government, usually claim the attacks but NATO officials say most stem from personal grudges and cultural misunderstandings rather than militant plots.
The threat of insider attacks means foreign soldiers working with Afghan colleagues deploy so-called "guardian angels" to provide protection.
Afghan soldiers and police are taking over responsibility for battling the militants from 100,000 NATO troops who will leave by the end of next year -- more than a decade after a US-led invasion brought down the Taliban regime.
Karzai stoked tensions with Washington on Sunday by accusing the US of colluding with the Taliban to justify its presence in Afghanistan, stunning American officials during a visit by the new Pentagon chief.