iStock/Thinkstock(KABUL, Afghanistan) — Two Americans have been killed in an attack near a coalition base near Kabul, Afghanistan, officials said. In addition to the deaths of the U.S. service member and U.S. civilian, two additional U.S. civilians were injured in Wednesday’s attack.

“U.S. service member and one U.S. civilian died as a result of wounds sustained in Kabul, Afghanistan today,” according to a statement released by U.S. Forces Afghanistan. “One U.S. service member and two U.S. civilians also sustained wounds and are currently stable.

“The two individuals were killed during an attack near a coalition base by an unknown assailant, who was later killed. They were conducting duties as part of the larger NATO mission to Train, Advise, and Assist the Afghan security services. An investigation is being conducted to determine the exact circumstances of the event.”

There were unconfirmed media accounts in Kabul that the incident may have been an insider attack and that the attacker was wearing an Afghan Army uniform.

“Anytime we lose a member of our team, it is deeply painful,” said Gen. John W. Nicholson, commander of U.S. Forces-Afghanistan and Resolute Support. “Our sympathies go out to the families, loved ones, and the units of those involved in this incident. To those who continue to target Coalition forces, ANDSF, and Afghan civilians, RS and USFOR-A will continue to pursue our Train, Advise, and Assist mission to help our partners create a better Afghanistan.”

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