Several NATO countries scrambled jets on April 23 after a pair of Russian bombers approached their airspace over the North Sea.
The Dutch Defense Ministry identified the planes as two Russian TU-95s. It said the Russian jets were escorted by aircraft from the Netherlands, Britain, and Denmark until they departed.
The British Defense Ministry said the Russian planes flew in international airspace at all times.
Both the British and the Dutch defense departments said similar incidents involving Russian jets have occurred before, including several in 2013.
Reuters news agency cites defense analysts as saying Russia uses such surveillance flights to remind the world of its military power and to probe other countries' air defense systems.