"Air defense missile units taking part in the snap combat readiness exercises for aviation groups and anti-air defense troops in Russia's Central Military District have been redeployed to Kapustin Yar and Ashuluk in the Astrakhan Region," Russia's Ministry of Defense said.
The units will be tasked with target coverage.
Additionally, over 100 aircraft are set to be deployed for the drills in the next 24 hours, according to the ministry.
The four-day drills involving 12,000 military personnel, up to 250 aircraft and 700 pieces of military hardware were launched on Monday on President Vladimir Putin's orders.
Meanwhile, Sweden, Norway and Finland along with other European nations and the United States take part in massive fighter jet drills, dubbed the Arctic Challenge Exercise 2015. The war games, held in close proximity to the Arctic Circle, involve some 115 aircraft, including tanker aircraft and 3,600 personnel. They will last until June 2, 2015.