The Ukrainian military admitted it has faced heavy setbacks in the fight to retain control over the strategically important town of Lyman in the eastern Donbass region.
Pro-Russian separatists claimed on Friday full control of Lyman. The town sits at the crossroads to larger metropolitan areas and is the site of a major railway hub.
On the same day the General Staff of Ukraine's armed forces also said fighting was taking place inside the town and that Russian troops were attempting to force the Ukrainian defenders out of it.
On Saturday, the General Staff said the Russian side was "trying to establish itself in the Lyman area" and was now shelling two villages south of the town - Ozerne and Dibrova - with grenade and rocket launchers, indicating a shifting of the front lines from the north.
British military intelligence said that Russia had captured "most" of Lyman, "in what is likely a preliminary operation for the next stage of Russia's Donbass offensive."
"Lyman is strategically important because it is the site of a major railway junction, and also gives access to important rail and road bridges over the Siverskyy Donets River. In the coming days, Russian units in the area are likely to prioritize forcing a crossing of the river," the agency wrote on Saturday in its regular Twitter update on the war.
Lyman sits west of Sievierodonetsk, the easternmost Ukrainian city still under Ukrainian control and where fierce battles are taking place as Russia aims to encircle the area.
Sievierodonetsk was the target of Russian attacks overnight but advances on the city and its suburbs were repelled, the General Staff's situation report said.
In nearby Bakhmut, the Russians tried to get behind the Ukrainian forces and cut off the supply routes, but those efforts also failed, the report said.
