Afghan soldier kills two US civilian trainers

An Afghan soldier has killed two US civilian trainers and another Afghan soldier near the northern city of Mazar-e-Sharif, Nato's International Security Assistance Force (Isaf) says.

The incident took place during weapons training for Afghan recruits.

Last week, a renegade Afghan soldier killed three UK troops in Helmand province in the south of the country.

There are currently about 150,000 Nato-led troops in Afghanistan fighting the Taliban insurgency.

One Nato soldier and one Afghan soldier were wounded in the incident at Camp Shaheen, Isaf said.

Afghanistan's ministry of defence and Isaf are investigating the shootings.

"Our joint investigation will find out how such an event could have occurred to help us prevent any future acts," Afghan ministry of defence spokesman Maj Gen Zahir Azimi said.

"The actions of this individual are not representative of the thousands of men and women who train and fight side-by-side with Isaf every day to protect their fellow citizens from insurgent brutality," said Isaf spokesman Brig Gen Josef Blotz.

Afghan President Hamid Karzai has just closed a major international conference on his country with a call for his country to control its own security by 2014.