Russian forces pounded the eastern Ukrainian city of Avdiivka for the fourth day in a row on Friday.
In attacks elsewhere in Ukraine, a Russian missile strike killed one person in the city of Pokrovsk, also in the east, while a drone attack in the south killed a women and seriously injured her husband.
"The fighting has been going on for four consecutive days," Vitaliy Barabash, head of the city's military administration, told Ukrainian national television.
"They have substantial reserves of personnel and equipment. Avdiivka is completely ablaze. They shoot, using everything they have. The hospital is again under fire, as are administrative buildings and our volunteer center."
Russia has focused its campaign along the 1,000-km (600-mile) front on the eastern regions of Donetsk and Luhansk.
Russia's representative to the United Nations, Vasily Nebenzia, said the intensified battles in the east signified a new stage in its campaign.
"Russian troops have, for several days now, switched over to active combat action practically throughout the entire front line," Nebenzia told a session of the UN Security Council, Reuters reported.
"The so-called Ukrainian counteroffensive can therefore be considered finished."
Russian forces abandoned the western bank of the Dnipro River in the Kherson region late last year, but continue to shell towns there from positions on the eastern bank.
