The Russian military has launched a massive exercise involving 250 aircraft and other weapons.
The drills will involve air force and air defence units of the central, western and southern military districts totalling 12,000 servicemen, the defence ministry said.
Combat aircraft will deploy to temporary bases and air defence systems will be sent to the Ashuluk and Kapustin Yar shooting ranges in southern Russia for training with live ammunition.
Russian Bear Bomber
Long-range Russian bombers will launch cruise missiles at practice targets at a Siberian firing range, the ministry added.
The exercise is part of a series of Russian military manoeuvres taking place amid tensions with the West over Russian actions in Ukraine.
The current drills are preparation for even more massive Centre-2015 manoeuvres set for later this year.