Russia is moving more tanks near the border with Ukraine, defense-intelligence firm Janes said, reinforcing Western concerns about reports of a buildup of Russian military forces close to its neighbor.

At least a battalion of T-80U main battle tanks were deployed to a railway station in the Voronezh region, according to social-media footage from Nov. 7, London-based Janes said in an analysis provided to Bloomberg News. The tanks appear headed for the Pogonovo training ground, the same one where a Russian military buildup in the spring sparked Western demands for a pullback, according to Janes.

Fighting has picked up at times in recent weeks between Ukrainian forces and Russian-backed separatists in the east of the country. Ukraine used a Turkish-made drone for the first time to attack a separatist howitzer in response to a strike that killed one soldier and wounded another on Oct. 26. Last week, Janes said it identified the deployment of tanks and self-propelled artillery from the same Russian division to the Bryansk and Kursk regions on Ukraine’s northern border on Oct. 28 and 29.