Russian missile strikes reportedly hit Ukraine's capital Kyiv and other cities on Saturday, as Moscow said its troops had seized the urban area of Mariupol and only a small contingent of Ukrainian fighters remained inside a steelworks in the besieged southern port, according to reports by Reuters.
Russia's claim to have all but taken control of Mariupol, scene of the war's heaviest fighting and worst humanitarian catastrophe, could not be independently verified. It would be the first major city to have fallen to Russian forces since the Feb. 24 invasion.
Explosions were also reported in Ukraine's capital Kyiv and the western city of Lviv on Saturday morning, prompting concerns that Russia stepped up attacks on Ukraine in retaliation for the sinking of its flagship missile cruiser Moskva by Ukrainian forces.
Russia said that it had destroyed production buildings of an armored vehicle plant in Kyiv and a military repair facility in the city of Mykolaiv, the Interfax news agency quoted Russia's defence ministry as saying on Saturday.
Separately, Reuters reported that the head of Russia's navy met with sailors from Moskva, the Russian Black Sea flagship that sank on Thursday.
A senior U.S. Defense official told NBC News that the Pentagon now believes Ukraine's claims that it sank the Moskva.