https://www.bbc.co.uk/news/world-europe-64957792
By Henri Astier
BBC NewsA Russian fighter jet has collided with a US drone, causing the unmanned US aircraft to crash into the Black Sea, the American military says.
It says the drone was on a routine mission in international airspace when two Russian jets tried to intercept it.
The US European Command said Tuesday's crash was the result of an "unprofessional act by the Russians".
Russia said the drone crashed after a "sharp manoeuvre", and denied that the two aircraft made contact.
The Russian defence ministry also said the US aircraft was flying with its transponders turned off. Transponders are communications devices that allow the aircraft to be tracked.
The incident happened at about 7:03 Central European Time, according to the US military.
"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," the statement said.
Several times before the collision the Su-27 fighter jets dumped fuel on the drone in a "reckless, environmentally unsound and unprofessional manner".
MQ-9 Reaper drones are surveillance aircraft with a 20m (66ft) wingspan.
White House spokesman John Kirby said Russian intercepts of US aircraft were not uncommon over the Black Sea, but it was the first time that one had resulted in a crash.
Tensions have risen in the region ever since Russia's annexation of Crimea in 2014.
Since Russia's full-scale invasion of Ukraine the US and the UK have stepped up reconnaissance and surveillance flights, though always operating in international airspace.