Image copyright EPA Image caption Maj Gen Greene is reported to be the most senior US soldier to die in combat since the Vietnam War

A US general has been killed in an attack by an Afghan soldier at a British-run military academy near Kabul, US officials say.

Maj Gen Harold Greene is the highest ranking US military official to have been killed since US-led combat operations in Afghanistan began.

At least 15 soldiers - two British, several Americans and generals from Germany and Afghanistan were wounded.

Officials said the Afghan soldier who opened fire had been shot dead.

Gen Greene was the deputy commanding general for the Combined Security Transition Command, involved in preparations for the withdrawal of coalition troops at the end of the year.

Correspondents say that the attack raises new doubts about Nato's ability to train Afghan forces as Western countries gradually withdraw.

The Pentagon described "insider attacks" as a "pernicious threat".

Media playback is unsupported on your device Media caption The BBC's David Loyn says the Afghan Ministry of Defence has confirmed that several foreign soldiers have been injured

From the end of this year just under 10,000 American troops will remain, with all withdrawing by the end of 2016.

The BBC understands the shooting at Camp Qargha happened after a dispute broke out.

The attacker was a soldier who was recruited three years ago, Afghan defence ministry sources told the BBC.

The Pentagon described it as an isolated attack and insisted that there has been no breakdown of trust between coalition soldiers and their Afghan counterparts.

Image copyright AP Image caption There was high security at the camp in the aftermath of the shooting

Image copyright Reuters Image caption The Pentagon has described the violence as an isolated attack

Afghan 'Sandhurst'

The incident is said to have occurred late morning or lunchtime after an argument between Afghans and an armed Afghan soldier.

The Afghan soldier opened fire from a guard post at a large group of senior Afghan and international troops.

By the time he had emptied the magazine of his US-issue M16 rifle, more than a dozen people had been shot, our correspondent says.

Gen Greene is reported to the most senior US soldier to die in combat since the Vietnam War.

The Afghan commander of the British-led officers' academy, Gen Gulam Sakhi, was among those wounded.

The training academy, which first took cadets last October, is modelled on UK military academy Sandhurst.

It will be the only British military presence in Afghanistan when operations end this year.

Media playback is unsupported on your device Media caption Rear Admiral John Kirby: "The insider threat is a pernicious threat"

The military history syllabus of the academy - set in a long ridge of hills close to Kabul - includes analysis of Afghan tactics in past wars against the British as well as during the mujahideen wars against the Soviet army.

There were 10,000 applicants who applied for its first intake.