Russia's navy has launched snap military exercises involving its fleet in the Caspian Sea, a news report said.
The drill will last seven days and involve about 10 naval vessels and 400 sailors, the Defence Ministry said, Interfax reported. The Caspian Sea is bordered by Iran, Russia, Kazakhstan, Turkmenistan and Azerbaijan, and the region is crisscrossed by oil and natural gas pipelines.
Russia has boosted the number of snap military drills it holds since tensions have risen with neighbor Ukraine.
NATO has said Russia's military exercises in its Western Military District have boosted its troop presence to about 40,000 near the border with Ukraine, where Moscow-backed President Viktor Yanukovych fled from power in February.