A Russian Su-27 fighter jet collided with a U.S. MQ-9 Reaper drone over the Black Sea on Tuesday, the US military’s European Command said. The collision caused the latter to crash into the sea.

“Our MQ-9 aircraft was conducting routine operations in international airspace when it was intercepted and hit by a Russian aircraft, resulting in a crash and complete loss of the MQ-9,” said US Air Force General James Hecker, commander of US Air Forces Europe and Air Forces Africa. “In fact, this unsafe and unprofessional act by the Russians nearly caused both aircraft to crash.”

Despite the recent incident, US and allied forces will continue to operate in the area, the statement added. There is no word on the incident from Russia.

MQ-9 Reaper drones are oversized unmanned aircraft designed for high-altitude surveillance.

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