Ukrainian forces faced relentless Russian attacks on Bakhmut in its eastern Donetsk region, with both sides reporting mounting enemy casualties as they battled across a small river that bisects the ruined town and now marks the front line.
Ukraine's President Volodymyr Zelenskiy said late on Sunday his forces had killed more than 1,100 Russian soldiers in the past few days as they fought for control of Bakhmut.
"In less than a week, starting from the 6th March, we managed to kill more than 1,100 enemy soldiers in the Bakhmut sector alone, Russia's irreversible loss, right there, near Bakhmut," Zelenskiy said in his nightly video address.
Russian forces sustained 1,500 "sanitary losses", soldiers wounded badly enough to keep them out of action, Zelenskiy said.
Dozens of pieces of enemy equipment were destroyed as were more than 10 Russian ammunition depots, he said.
Russia's defence ministry said earlier in the day that its forces had killed more than 220 Ukrainian service members over the past 24 hours in the Donetsk direction.
Reuters could not independently verify battlefield reports and neither side gave details of their own casualties.
Ukraine forces control west of the nearly deserted mining town of Bakhmut, while Russia's Wagner mercenary group controls most of the eastern part, with the Bakhmutka River that flows through the town marking the front line, British intelligence said in an update over the weekend.
Wagner founder Yevgeny Prigozhin said on Sunday the situation in Bakhmut was "tough, very tough".
"The closer we are to the centre of the city, the harder the fighting ... The Ukrainians throw in endless reserves. But we are advancing and we will be advancing," Prigozhin said in an audio statement released by his press service.
He also said Russian army members helped his troops with ammunition.
"Yesterday, we got 15 truckloads, today we got 12. And I think we will continue to receive them," he said, adding there was no conflict between his fighters and Russian troops.
Prigozhin had previously complained that Russia's top brass was deliberately starving his men of ammunition, an allegation the defence ministry rejected.
Prigozhin said Wagner "will begin to reboot" and start hiring once Bakhmut is captured, adding he wanted to turn his private military company into an "army with an ideology" that would fight for justice in Russia.
Wagner has already opened recruitment centres across 42 cities to replenish its ranks.