Russia opened the 201st military base in 2004 with a contingent of several thousand personnel from a motorized infantry division stationed in Tajikistan since the Cold War. The move was widely seen as Moscow's attempt to counter the growing influence of the United States in Central Asia.
"The units will train in combat deployment, and will organize and conduct a special combat operation against illegal militant groups intruding from a neighboring state," the source said.
Soldiers will also undertake 200km (125-mile) forced marches over rugged desert and mountain terrain.
In all, about 2,000 men, along with armored vehicles, artillery, missile and air-defense batteries will be involved in the exercises, which will continue through August 18. The final phase will include live firing missions and involve ground attack aircraft and combat helicopters.
