A Nato-led soldier fighting insurgents in Afghanistan was shot dead on Saturday by a man in an Afghan army uniform in southern Afghanistan, the latest in a series of "insider" attacks, the alliance said.
"I can confirm that an individual wearing Afghan national army uniform turned his weapon against ISAF members in southern Afghanistan, killing one," an International Security Assistance Force spokesman told AFP.
The incident happened after a "verbal argument" between an Afghan soldier and foreign troops in a joint camp in Nad Ali district of Helmand province, said Ahmad Zeerak, the Helmand governor's spokesman.
The Afghan soldier was wounded after the foreign troops returned fire and he has been taken to the hospital, he said.
Marjan Haqmal, the district police chief, said that up to three foreign soldiers were either killed or wounded in the attack.
Shootings by Afghan forces have taken an increasing toll on Nato troops and have seriously undermined trust between Nato forces and their Afghan allies in the fight against hardline Islamist Taliban insurgents.
In the most recent "insider" attacks, at least two Afghan soldiers attacked Nato-led forces in western Afghanistan on Saturday, injuring a Spanish soldier, officials said.
The injured Afghan soldier and the other assailant were captured by the Afghan National Army and a third man was suspected of involvement, officials said.
The Afghan conflict has seen a surge in insider attacks this year, with more than 50 ISAF troops killed by their colleagues in the Afghan army and police.
There are presently around 100,000 US-led forces fighting alongside Afghan security forces against a Taliban-led insurgency that has been raging in the war-torn country since a US-led invasion toppled the Islamist regime in late 2001.
Nato combat forces are scheduled to withdraw from Afghanistan by the end of 2014.