Russian military officials say they have launched four days of military exercises in central and western regions of Russia, including most of western Russian and areas that border Ukraine.
Interfax quoted Russian Air Force spokesman Igor Klimov as saying that the August 4 to August 8 exercises include the use of 100 military aircraft.
Klimov said the exercises were the first in a series of military maneuvers aimed at enhancing coordination within the air force and conducting missile practice.
He said the aircraft involved include Su-27 and MiG-31 fighter jets, Russia's new Su-34 bomber, and several types of military helicopters.
The exercises come as pro-Russian separatists battle Ukrainian government forces in eastern Ukraine.