Russia says it has hit hundreds of military targets in Ukraine overnight, destroying command posts with air-launched missiles, while authorities in the western city of Lviv, which had escaped heavy bombardment, said a missile attack killed seven.
The Russian defence ministry said in a statement on Monday it had destroyed 16 Ukrainian military facilities in the Kharkiv, Zaporizhzhia, Donetsk and Dnipropetrovsk regions and in the port of Mykolayiv, in the south and east of the country.
It added that the Russian air force had launched strikes against 108 areas where Ukrainian forces were concentrated and Russian artillery struck 315 Ukrainian military targets overnight.
Driven back by Ukrainian resistance in the north, the Russian military has refocused its ground offensive in the two eastern provinces known as the Donbas, while launching long-distance strikes at other targets, including the capital, Kyiv.
It is now trying to take full control of the Ukrainian port city of Mariupol, which has been besieged for weeks and which would be a huge strategic prize, linking territory held by pro-Russian separatists in the east with the Crimea region Moscow annexed in 2014.
Ukrainian authorities said missiles struck military facilities and a car tyre service point in Lviv, which is just 60 kilometres from the Polish border.
Lviv mayor Andriy Sadoviy said seven people were killed and 11 were wounded. The blast shattered windows of a hotel housing Ukrainians evacuated from elsewhere in the country, he added.
"Seven peaceful people had plans for life, but today their life stopped," the mayor said.
Russia denies targeting civilians and rejects what Ukraine says is evidence of atrocities, saying Ukraine has staged them to undermine peace talks.
Moscow calls its action, launched almost two months ago, a special military operation to demilitarise Ukraine and eradicate what it calls dangerous nationalists.
Western capitals and Kyiv accuse Russian President Vladimir Putin of unprovoked aggression.
Ukrainian Prime Minister Denys Shmyhal said troops in the pulverised port of Mariupol were still fighting on Sunday, despite a Russian demand to surrender.
"The city still has not fallen," he told ABC's This Week program, adding that Ukrainian soldiers continued to control some parts of the southeastern city.
Two captured British men who fought with Ukrainian forces in Mariupol appeared on Russian state TV on Monday and asked to be exchanged for pro-Russian politician Viktor Medvedchuk who is being held by Ukrainian authorities.
It was unclear how freely the two men, Shaun Pinner and Aiden Aslin, were able to talk.
Medvedchuk, meanwhile, was shown in a video released by Ukraine's SBU intelligence service asking to be swapped for the defenders of Mariupol and citizens struggling to leave. It was also unclear how freely Medvedchuk was speaking.
Russia said on Saturday it had control of urban areas, though some Ukrainian fighters remained in the Azovstal steelworks, one of Europe's biggest metallurgical plants, which cover more than 11 square kilometres and overlook the Sea of Azov.
On the streets of Mariupol, small groups of bodies were lined up under colourful blankets, surrounded by shredded trees and scorched buildings.
Residents, some pushing bicycles, picked their way around destroyed tanks and civilian vehicles while Russian soldiers checked the documents of motorists.
On the eve of the war, Mariupol was the biggest city still held by Ukrainian authorities in the Donbas, which Moscow has demanded that Ukraine cede to pro-Russian separatists.
Taking Mariupol would unite Russian forces on two of the main axes of the invasion, and free them up to join an expected new offensive against the main Ukrainian force in the east.
Ukraine and Russia have failed to agree about humanitarian convoys for the evacuation of civilians from war-affected areas for the second day, Ukraine's Deputy Prime Minister Iryna Vereshchuk said.
About four million Ukrainians have fled the country, cities have been shattered and thousands have died since the start of the invasion on February 24.
Serhiy Gaidai, the governor of the Luhansk region, said in a television speech that Russian forces had advanced overnight and taken the town of Kreminna, some 300km north of Mariupol.
Authorities could no longer evacuate people from that town, but evacuations continued elsewhere.
Australian Associated Press
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