WASHINGTON: A Russian Su-27 fighter jet intercepted and struck the propeller of a US military MQ-9 “Reaper” surveillance drone on Tuesday, causing it to crash into the Black Sea, the Pentagon said, in the first such incident since Russia’s invasion of Ukraine over a year ago.

NATO’s Supreme Allied Commander Europe, US Army General Christopher Cavoli, briefed NATO allies about the incident, which was roundly condemned by the White House and the Pentagon — which warned of the risk of escalation. The State Department said it was summoning Russia’s ambassador over the incident.

There was no immediate comment from Moscow.

Two Russian Su-27 jets carried out what the US military described as a reckless intercept of the American spy drone before one of them collided with it at 7:03 a.m. (0603 GMT).

Several times before the collision, the Russian fighter jets dumped fuel on the MQ-9 — possibly trying to blind or damage it — and flew in front of the unmanned drone in unsafe maneuvers, the US military said.

“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,” US Air Force General James Hecker, who oversees the US Air Force in the region, said in a statement.

“In fact, this unsafe and unprofessional act by the Russians nearly caused both aircraft to crash.”