Hundreds of Russian troops started military exercises in southern Russia near the border with Ukraine on Tuesday, in a show of strength before a summit on the Ukraine crisis in the Belarussian capital of Minsk.
News agencies quoted military officials as saying that about 2,000 Russian reconnaissance troops had started large-scale exercises in the southern military district.
Separately, more than 600 soldiers had started training in the southern Crimean Peninsula, and in Kamchatka, in Russia's east, 2,500 soldiers of the Pacific Fleet and joint forces were checked for military readiness.
The maneuvers in southern Russia would include training on tracking devices to determine enemy movements in bad visibility. In Crimea, soldiers would undergo tactical and shooting training, the news agencies reported.
The leaders of Ukraine, Russia, France and Germany are expected to meet in Minsk on Wednesday to seek an end to fighting in eastern Ukraine, which has killed more than 5,000 people since last April.
The West accuses Russia of backing an advance in recent weeks by separatists, which scuppered a cease-fire agreed last September. Moscow denies it is involved.