Russia has launched its biggest military manoeuvres since Soviet times, involving 160,000 troops and about 5,000 tanks across Siberia and the far eastern region.
President Vladimir Putin watched some of the drills on Tuesday on Sakhalin Island in the Pacific.
The manoeuvres are part of recent efforts to boost the military’s mobility and combat readiness.
Dozens of Russia’s Pacific Fleet ships and 130 combat aircraft also took part in the drills, which began on Friday and continue through this week.
As part of the drills held across several time zones, some Army units deployed to areas thousands of kilometres away from their bases.
Russia’s Deputy Defence Minister Anatoly Antonov assured foreign military attaches that the exercise was part of regular combat training and wasn’t directed against any particular nation.