The Russian Defence Ministry issued a statement on Monday saying that one of its Su-27 had intercepted a German patrol aircraft and a US spy plane over the Baltic Sea.
Earlier in the day, the Estonian Defence Forces stated that Eurofighter Typhoon jets belonging to the German Air Force will fly this week in the skies over Estonia under the cover of darkness.
“Flight operations in Estonian airspace will last from Monday to Friday [in the dark] until 21:00 [19:00 GMT],” the press office for the defence forces said in a statement.
Flights are carried out on the basis of agreements between NATO countries in specially designated areas.
At the 2012 NATO summit in Chicago, the mission was extended indefinitely.
NATO aircraft have intensified reconnaissance activities near the Russian border over the past month. Moscow has warned that such regular flights by US and NATO aircraft near Russia's border poses the risk of accidental escalation.