3 Americans Killed In An 'Insider Attack' At Kabul's Airport

Three American contractors were killed and a fourth was wounded by an Afghan soldier at the military airport in the capital Kabul, an Afghan air force official told Reuters on Thursday.

"It is unclear yet why he shot these advisers and no one else was there to tell us the reason," the official said, asking not to be named because he was not authorized to give statements to the media. "An investigation has been opened."

The international force in Afghanistan confirmed the shooting took place on Thursday evening. Kabul's airport is a major gateway for the thousands of contractors and aid workers still operating in the troubled country and a number of international carriers fly there, including Emirates, Turkish Airlines, and FlyDubai.

This would mark only the latest "insider attack" in the country, in which members of the uniformed security services have turned on either their colleagues or people they are supposed to be protecting. In August, an American two-star general was killed in Afghanistan in an insider attack, making him the highest-ranking US officer killed during the 12-year-long operation in the country.

The US ended its combat operation in Afghanistan in December of 2014. The country's security is now largely the responsibility of Afghan security forces that have taken unsustainable losses in their fight against the Taliban and that are penetrated by the Taliban and its supporters.

(Reporting by Jessica Donati; Editing by Kevin Liffey)