On Monday, two Russian battalion tactical groups with some 60 tanks managed to break through Ukrainian lines after a three-day battle and take the town of Kreminna in Luhansk region, Ukrainian officials said. From Kreminna, the Russian forces are attempting to push through forested areas in the direction of Slovyansk…

On Tuesday, columns of Ukrainian reinforcements were heading toward Donbas from central Ukraine, with troops, ammunition and artillery pieces on the roads. In Slovyansk, men in uniform began to outnumber civilians on once-busy streets, many of them stocking up on dwindling supplies in the few remaining supermarkets before heading back to the front. Fuel stations were already closed. In Luhansk, electricity was down in most towns after Russian shelling disrupted the main power line.

Slovyansk holds high symbolic importance for both sides. The Donbas conflict began here in 2014, when Russian military veterans led by a former FSB intelligence service colonel seized the local administration. A Ukrainian military offensive retook Slovyansk and nearby Kramatorsk weeks later, but failed to seize the region’s main cities, Donetsk and Luhansk.