Fighting raged in and around Bakhmut as Ukraine mocked Russian claims to have captured the administrative centre of the eastern Ukrainian city, saying Russian forces had raised a victory flag over "some kind of toilet".
Finland, which shares a 1,300-km (810-mile) border with Russia, will later on Tuesday join NATO, just over a year after Russia invaded Ukraine, partly in response to what Russia said the alliance's aggressive expansion eastward.
The battle for the mining city and logistics hub of Bakhmut has been one of the bloodiest of the conflict with heavy casualties on both sides and the city largely destroyed.
Yevgeny Prigozhin, head of the Wagner mercenary force spearheading the siege, said on Sunday his troops had raised a Russian flag on the city-centre administrative building even though Ukrainian soldiers still held some western positions.
But Ukraine's military poured scorn on that claim and said fighting was raging around the city council building, as well as in other nearby towns.
"Bakhmut is Ukrainian and they have not captured anything and are very far from doing that," Serhiy Cherevatyi, spokesperson for the eastern military command, told Reuters.
"They raised the flag over some kind of toilet. They attached it to the side of who knows what, hung their rag and said they had captured the city. Well good, let them think they've taken it," Cherevatyi added by telephone.
The Ukrainian armed forces General Staff said in an evening statement 45 enemy attacks had been repelled in total in the last 24 hours, with Bakhmut at the "epicentre of operations" along with the cities of Avdiivka and Maryinka further south.
Reuters could not verify the battlefield reports.
'WAITING FOR ORDERS'
On the edge of a part of Donetsk province under Russian control, Bakhmut had a population of 70,000 before Russia invaded Ukraine in February last year.
Russian forces, bogged down in a war of attrition after a series of setbacks, are seeking a victory from their winter offensive but have suffered huge casualties around Bakhmut.
Ukrainian military commanders have said their own counteroffensive - backed by newly delivered Western tanks and other hardware - is not far off but have stressed the importance of holding Bakhmut and inflicting losses in the meantime.
"People are ready for the counteroffensive, all we are waiting for is marching orders and details on which direction we should go forward on - Bakhmut, Soledar or anywhere else," said a 35-year-old soldier of a tank brigade near Bakhmut, who used the nom-de-guerre Polyot.
Russia launched up to 17 Iranian-made Shahed drones overnight, Ukraine's air force command said early on Tuesday, with its air-defence systems destroying 14 of them.
Yuriy Kruk, head of the regional military administration in the Black Sea port city of Odesa, said the region was struck by several drones and there was damage but he did not specify the extent.
Four civilians were killed and three wounded in Ukraine-controlled Donetsk, its governor, Pavlo Kyrylenko, said in a statement.
'DRIVING A WEDGE'
Russia calls its invasion of Ukraine a "special military operation" to rid it of Nazis.
Tens of thousands of Ukrainian civilians and soldiers on both sides have been killed. Russia has destroyed Ukrainian cities and forced millions of people to flee their homes, and it claims to have annexed nearly a fifth of Ukraine.
The West calls the war an unprovoked assault to subdue an independent country and has provided Kyiv with weapons while seeking to punish Russia with sanctions.
Russian Foreign Minister Sergei Lavrov accused the West of trying to drive a wedge between Russia and China, and attempting to wreck Russia's planned summit with African countries. He also said the European Union's hostile stance towards Moscow meant it had "lost" Russia.
Echoing that anger, Russia's parliament speaker said Western leaders have blood on their hands for supporting Ukraine's President Volodymyr Zelenskiy and the support had led to the creation of a "terrorist state" at Europe's centre.
Vyacheslav Volodin, an ally of President Vladimir Putin, said the killing of prominent war blogger Vladlen Tatarsky in a bomb attack in St Petersburg over the weekend was a "terrorist act" committed by Kyiv.
Ukraine blamed "domestic terrorism" for the blast.
NATO will welcome Finland as its 31st member in a flag-raising ceremony at its headquarters on the outskirts of Brussels.
Russia's invasion of Ukraine prompted Finns to seek security under the umbrella of NATO's collective defence pact, which states that an attack on one member is an attack on all.
Russia has also said it would strengthen its military capacity in its western and northwestern regions in response to Finland's accession.
(Additional reporting by Nick Starkov, Ron Popeski, Lidia Kelly, Mark Trevelyan and Felix Light; Writing by Lincoln Feast; Editing by Stephen Coates, Robert Birsel)
