Russia said on Sunday that, it had carried out a devastating retaliatory strike in eastern Ukraine to avenge a recent deadly attack on its troops, a claim quickly denied by Kyiv.
More than 600 Ukrainian servicemen were killed by a missile strike on troops stationed in two buildings used as barracks in Kramatorsk, said a Russian Defence Ministry statement.
Russia described the attack as a "retaliatory strike" following Ukraine's New Year's Eve missile salvo in the eastern Ukrainian town of Makiivka, which Moscow said killed 89 of its soldiers.
Ukraine's armed forces rejected Russia's claim about the Kramatorsk attack.
The Russian statement did not say when exactly the strike had taken place -- only that Russian intelligence had "over the past 24 hours" located
more than 1,300 Ukrainian troops in two buildings in Kramatorsk.
The industrial city, in the eastern Donetsk region, has been the target of repeated Russian missile attacks.
While Russia conceded 89 troops had died, the worst single reported loss from a Ukrainian strike since the war began last February, one statement from Ukraine's military claimed the losses came to more than 400.
Russian President Vladimir Putin ordered a 36-hour ceasefire to allow Orthodox Christians to mark Christmas, which was celebrated Saturday in Russia and Ukraine.
In his evening address on Sunday, Ukrainian President Volodymyr Zelensky denounced "Russian shelling of Kherson with incendiary ammunition right after Christmas", in the southeast.