3 US Contractors Shot Dead at Kabul Airport Gunman may have been an Afghan soldier By Newser Editors and Wire Services Posted Jan 29, 2015 3:24 PM CST 71 comments Comments File photo of Afghan security forces in Kabul. (AP Photo/Massoud Hossaini) (Newser) – Another insider attack? A gunman at an airport in Kabul killed three American contractors today, reports the AP. Reuters reports that the shooter was an Afghan soldier, though that has not been confirmed. ABC News quotes a US official as saying that the gunman was at least wearing the uniform of a national police officer, but it was unclear whether he was actually a member of the force. The contractors have not been identified. "It is unclear yet why he shot these advisers, and no one else was there to tell us the reason," says an Afghan air force official. "An investigation has been opened." The Washington Post reports that attacks by Afghan security forces on their supposed allies have killed more than 140 members of the US-led coalition in recent years.