Some of 2,000 servicemen are taking part in "large-scale" air-defense exercises in southern Russia, Crimea, and the breakaway Georgian regions of Abkhazia and South Ossetia, according to RIA Novosti.
This comes as 6 NATO warships have entered Black Sea for training on Wednesday to train with ships from the Bulgarian, Romanian and Turkish navies.
The military's Southern Federal District announced March 5 that 500 pieces of heavy weaponry or military equipment were being used in the drills conducted by Russia’s air-defense units, whose job is to repel attacks by aircraft and missiles.
It was not immediately clear how long they would last.
Russia annexed Crimea from Ukraine in March 2014 and recognized Abkhazia and South Ossetia as independent countries in 2008 -- both moves that have been widely condemned by international community as illegitimate.