This article was written and first published on Radio Free Europe on September 7, 2018. Read the original article here.

A two-seat Ukrainian fighter jet has crashed during a joint exercise with NATO air forces, killing both the pilot and co-pilot, Ukraine's military says.

"A Sukhoi-27 plane crashed at around 5 p.m. local time during a training flight," the Armed Forces General Staff said in a statement on October 16, adding that "the bodies of the two pilots have been found."

The circumstances of the crash - which occurred in the Khmelnytskyy region, around 180 kilometers southwest of Kyiv - have yet to be clarified, it added.

The U.S. Air Forces in Europe and Africa said that it was aware of "reports claiming a U.S. casualty."

A statement said it "can confirm a U.S. service member was involved in this incident," but stopped short of confirming the American's death.

Personnel from the United States and seven other NATO member states are taking part in the Clear Sky drills, which run until October 21.

Members of a California Air National Guard unit are among the participants.

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