The Russian Ministry of Defence has confirmed that a USAF B-52H was spotted flying over neutral waters in the Baltic Sea, adding that the plane's sudden u-turn maneuver was made after it was picked up by Russian air defences.
"On March 15, 2019, a US Air Force B-52 aircraft with its transponder switched on performed a flight over international waters of the Baltic Sea parallel to Russia's territorial waters," the ministry said in a statement.
"The plane did not approach Russia's border closer than 150 kilometers, and turned around immediately after Russian air defence systems on combat duty tracked it," the statement added.
Earlier, online plane monitoring resource PlaneRadar reported spotting the nuclear-capable USAF B-52H Stratofortress, registration number 61-0009, flying over the Baltic Sea, and indicated that the plane had engaged in an "imitation" bombing run against the Russian Baltic Fleet base.
In 2017, the last time that a USAF B-52H was reported operating near Russia's borders over the Baltic Sea, an Aerospace Defence Forces Su-27 fighter was scrambled to intercept it and escort it out of the area.
According to MoD figures, Russia's air defence network detected and tracked over a thousand foreign spy planes and UAVs flying along Russia's borders in 2018.