Russian President Vladimir Putin ordered the drills last Friday and they began that night, according to reports from the RIA Novosti news agency. Putin flew to Sakhalin island off the eastern coast to oversee the games on Tuesday, Russia's presidential press service reported.

"The main purpose of the activities is to check the readiness of the military units to perform assigned tasks and evaluate of the level of personnel's training and technical preparation as well as the level of equipment of units with arms and military equipment," the Russian Defense Ministry said in a statement reported by Russian Television.