Dozens of people were still missing on Wednesday after a Russian missile strike on a shopping mall in central Ukraine two days ago that killed at least 18, while a regional governor said the situation was "very difficult" in Lysychansk in the east.
Ukraine said Russia had killed civilians deliberately when it pounded the mall in Kremenchuk. Moscow said the mall was empty and it had struck a nearby arms depot.
"Russian missile hit this location precisely. De-li-be-ra-te-ly ... It is clear that Russian killers received those exact coordinates," Ukraine's President Volodymyr Zelenskiy said in an evening video address. "They wanted to kill as many people."
Authorities said around 36 people were still missing.
Further east in Lysychansk in the Luhansk region, a key battleground in Russia's assault on the industrial heartland of Donbas, the governor reported increased military action.
"The situation in Lysychansk is very difficult," Luhansk Governor Serhiy Gaidai said on television.
"The Russians are using every weapon available to them ... and without distinguishing whether targets are military or not - schools, kindergartens, cultural institutions," he said.
"Everything is being destroyed. This is a scorched-earth policy."
Russia has denied targeting civilian areas during its four-month offensive against Ukraine. The U.N. says at least 4,700 civilians have been killed since Russia invaded on Feb. 24.
In the Dnipropetrovsk region, towards the east, Governor Valentyn Reznychenko said Russia had fired six missiles, three of which were shot down. Rescue workers were searching for people under rubble in the city of Dnipro, he added.
Reuters could not verify the account. The Russian Defence Ministry did not reply to an emailed request for comment.
Separately, Russia-installed officials said their security forces had detained Kherson city mayor Ihor Kolykhayev on Tuesday after he refused to follow Moscow's orders. A local official said the mayor was abducted.
Kherson, a port city on the Black Sea, sits just northwest of the Russian-annexed Crimean peninsula.
In the past few days, Ukrainians have also described attacks in the southern region of Odesa and Kharkiv in the northeast.
The Russian invasion, the biggest assault on a European state since World War Two, has driven up prices of food and energy worldwide and fuelled global security worries.
Finland and Sweden on Tuesday moved a step closer to joining the Western NATO military alliance, whose members have provided Ukraine with weapons, after Turkey dropped its opposition to their membership.
The development solidifies the alliance's response to Russia - particularly in the Baltic Sea, where Finnish and Swedish membership would give NATO military superiority.
'CRUELTY OF THIS WAR'
The Kremenchuk attack drew a wave of global condemnation.
"We have run out of words to describe the senselessness, futility and cruelty of this war," U.N. political affairs chief Rosemary DiCarlo told the Security Council.
While Kyiv said there was no military target in the area, Russia's defence ministry said its missiles had struck a nearby arms depot storing Western weapons, which exploded, causing the blaze that spread to the nearby Kremenchuk mall.
Moscow's assertion the mall was empty was contradicted by wounded survivors such as Ludmyla Mykhailets, 43, who said she had been shopping there with her husband when the blast threw her into the air "head first".
Zelenskiy accused Russia of being a "terrorist state" at the United Nations, urging the Security Council to expel Moscow from the United Nations. Russia accused Zelenskiy of using the address as a "PR campaign" for weapons.
Western countries have imposed sanctions on Russia, but so far have failed to curtail Moscow's main source of income: oil and gas export revenue, which has actually increased as the threat of supply disruption has driven up global prices.
At the end of its annual summit, the leaders of the Group of Seven nations announced a new approach - leaving Russian oil on the market while imposing a cap on its price.The United States also imposed sanctions on more than 100 new targets and banned new imports of Russian gold, acting on commitments made by the G7.