According to the US armed forces, two Russian Su-27 fighter jets intercepted the US drone in international airspace over the Black Sea on Tuesday morning in a “dangerous and unprofessional manner”. The fighter jets first drained fuel onto the drone, said the US Armed Forces’ Regional Europe Headquarters in Stuttgart (US Eucom). Then one of the fighter jets touched the propeller of the unmanned aerial vehicle, which then crashed.

“Our MQ-9 aircraft was performing routine operations in international airspace when it was intercepted and rammed by a Russian aircraft,” said US Air Force General James Hecker. “This resulted in the crash and complete loss of the MQ-9.”

Pentagon spokesman Pat Ryder said in Washington that the Russian fighter jet “damaged” the drone’s propeller. The unmanned aerial vehicle was then “not airworthy” and “uncontrollable”, after which it was brought down by the US armed forces.

According to Ryder, the Russian fighter jets had previously flown alongside the drone for around 30 to 40 minutes. The Russian plane was probably also damaged by the collision with the drone propeller, but was able to land at an undisclosed location.

The Pentagon spokesman did not say whether the US forces wanted to recover the drone from the Black Sea. He also gave no information about possible Russian attempts to get hold of the US drone and its valuable technology, saying only that Moscow had not recovered the drone.

After the incident, the US State Department announced that it had summoned the Russian ambassador to Washington. The United States wanted to express its “strong objection to this dangerous, unprofessional interception” of the drone, said ministry spokesman Ned Price. In Moscow, US Ambassador Lynne Tracy had already sent a “strong message” to the Russian Foreign Ministry.

However, the Russian Defense Ministry denied that the fighter jets were responsible for the crash of the drone. The fighter jets intercepted the US drone. But there was no “contact”. The fighter jets would not have used their weapons either. Rather, after an “abrupt maneuver” the drone went into an “uncontrolled flight with a loss of altitude” and then hit the water surface.

NATO diplomats in Brussels said they did not expect an escalation after the incident. A Western military official told the AFP news agency that diplomatic channels between Russia and the United States are likely to be activated. “I assume that diplomatic channels will mitigate that.”

The Black Sea includes Ukraine, against which Russia is at war, and the Crimean Peninsula, which Russia has annexed. The US has long been flying reconnaissance flights over the Black Sea, observing Russian naval units. According to the Pentagon, Russian fighter jets intercept US flights again and again. But that usually only means that fighter jets accompany flights for a while and possibly ask them to turn around.

Reaper drones can be used for surveillance flights, but also for missile and laser-guided bomb attacks. In recent years, the US armed forces have lost several drones of this type – either through crashes or enemy fire.