"On August 13, 2018, four Black Sea Fleet jets, with no Su-24 bombers among them, were conducting regular training flights over the waters of the Black Sea," the ministry said in a statement.
"After accomplishing their mission in the assigned area, the Russian jets detected a NATO military aircraft at the distance of over 30 kilometers [about 19 miles]," the ministry added.
According to the statement, the detected jet did not perform any maneuvers, did not deviate from its course and did not attempt to approach the Russian aircraft which were heading back to their base.
On Monday, the Royal Air Force said that two Eurofighter Typhoons followed six Russian Su-24 aircraft near the NATO airspace. The UK jets observed the Russian aircraft until they left the proximity to the NATO territory, the British military said.