STORY: A Ukrainian tank rumbled toward Bakhmut on Friday as Kyiv claimed its forces had advanced more than a mile around the shattered ruins of the eastern city.
Russian forces have fought for months to seize Bakhmut, without success.
The Russian Defense Ministry on Friday said that Ukraine had deployed more than 1,000 troops and up to 40 tanks in more than two dozen attempted attacks in the direction of the town of Soledar.
The military admitted it was "regrouping" its forces, suggesting its fighters had fallen back.
The leader of a Russian mercenary force gave a different assessment.
Yevgeny Prighozin, founder of the Wagner paramilitary group, said the defense ministry was lying, and Russian forces had been routed and forced to flee.
Reuters has been unable to verify reports of battlefield movement.
Ukraine this week released what it said was footage of its forces fighting near Bakhmut.
It shows soldiers exiting an armored vehicle, taking cover behind mounds of earth, and firing their weapons.
Kyiv said advances around the city were not a part of a planned spring counter-offensive, which it says has yet to begin.
Meanwhile inside Russia, the city of Saint Petersburg debuted what it said was a new anti-drone police unit.
Footage from Russia's interior ministry shows heavily armed officers on rooftops above the city's Palace Square.
The new unit comes after Moscow claimed a Ukrainian drone last week detonated above the Kremlin, in what Russia said was an attempt to assassinate President Vladimir Putin.
Ukraine denied attacking Moscow.