At least three US troops were wounded Saturday when an Afghan soldier opened fire at them at a military base in northern Afghanistan, the defence ministry said, in an apparent insider attack.

"Initial information shows three US soldiers visiting the base were wounded," ministry spokesman Mohammad Radmanish told AFP, adding that the attacker had been gunned down.

The so-called "green-on-blue" attack at Camp Shaheen close to Mazar-i-Sharif city is the latest in a string of incidents where Afghan soldiers have turned their weapons on international forces training them.

It comes as the United States is expected to send more troops into the lengthy conflict at a time when the Taliban are ramping up their campaign against the Western-backed government.

US-led NATO forces confirmed that American soldiers had been wounded in "an incident" at Camp Shaheen, without specifying a number.

"At this time we can confirm there are no US or NATO Resolute Support fatalities," the international coalition said in a brief statement.

"US soldiers have been wounded. One Afghan soldier was killed and one was wounded in the incident."

Green-on-blue attacks have been a major problem during NATO's long years fighting alongside Afghan forces.

Western officials say most insider attacks stem from personal grudges and cultural misunderstandings rather than insurgent plots.



(AFP)