Satellite imagery taken on Wednesday showed new deployments in western Russia, many of them within 10 miles (16 kilometers) of the border with Ukraine and less than 50 miles (80 km) from the Ukrainian city of Kharkiv, a private U.S. company said.
The images showed field deployment, military convoys, artillery and armoured personnel carriers with support equipment and troops. The images released by Maxar Technologies, which has been tracking the buildup of Russian forces for weeks, could not be independently verified by Reuters.
Most of the troops and equipment were positioned in smaller unit-sized formations on farmland and along tree lines, Maxar said on Wednesday.
On Tuesday, the U.S. company's images had shown a new deployment of more than 100 military vehicles and dozens of troop tents in southern Belarus near the Ukraine border.
Ukraine declared a state of emergency on Wednesday and Moscow said separatists in the east had asked for help to repel "aggression" as the United States stepped up efforts to deter an all-out invasion by imposing fresh sanctions.
Russia has consistently denied it plans to invade its neighbour but President Vladimir Putin has ordered Russian troops into eastern Ukraine for what he called peacekeeping after Moscow recognized the separatist regions of Donetsk and Luhansk as independent.
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