WESTERN IRAQ — A U.S. military KC-135 Stratotanker refuelling aircraft crashed in western Iraq while taking part in U.S. operations against Iran, killing six crew members. The crash was not due to hostile fire or friendly fire.

The crew members killed were Maj. John A. Klinner, 33, of Auburn, Alabama; Capt. Ariana G. Savino, 31, of Covington, Washington; Tech. Sgt. Ashley B. Pruitt, 34, of Bardstown, Kentucky; Capt. Seth R. Koval, 38, of Mooresville, Indiana; Capt. Curtis J. Angst, 30, of Wilmington, Ohio; and Tech. Sgt. Tyler H. Simmons, 28, of Columbus, Ohio. Maj. John A. Klinner, Capt. Ariana G. Savino, and Tech. Sgt. Ashley B. Pruitt were U.S. Air Force personnel, while Capt. Seth R. Koval, Capt. Curtis J. Angst, and Tech. Sgt. Tyler H. Simmons served in the National Guard.

Two KC-135 Stratotanker aircraft were involved in the incident; one landed safely and the other crashed. An Iraqi intelligence source said the crashed aircraft went down near Turaibil on the Iraqi-Jordanian border. U.S. Central Command described the crash as occurring over friendly airspace.

U.S. officials said the incident may have involved a midair collision and that investigations were ongoing. Iran's military claimed on state television that an allied group had targeted the refuelling plane with a missile. A U.S. official said at least five crew members were aboard the KC-135 aircraft when it crashed.

The crash was the fourth publicly acknowledged U.S. aircraft loss as part of operations against Iran. To date, the U.S. military has lost at least four aircraft during the U.S.-Israel war with Iran. In early March, three F-15 fighter jets were shot down in a friendly fire incident over Kuwait and all six crew members safely ejected.

Boeing manufactured the KC-135 Stratotanker in the 1950s and early 1960s. The KC-135 Stratotanker entered U.S. military service more than 60 years ago and has undergone various retrofits and upgrades. KC-135 tankers typically have a crew of three. The KC-135 allows combat aircraft to carry out longer missions without landing.

The U.S.-Israel war with Iran began with U.S. and Israeli air strikes on Iran, including one that killed Ayatollah Ali Khamenei. Seven American troops have been killed in combat during the Iran war, while about 140 service members have been injured, including eight severely.