Early on Tuesday, a Russian missile hit an apartment complex in the Ukrainian port of Mykolaiv.
The most recent attack on a city, according to a Reuters witness, came hours after the United States issued a warning that it will hold Russia responsible for war crimes.
The missile entirely demolished one wing of the building in the downtown area, leaving a sizable crater, and was one of three explosions that could be heard early on Tuesday in the southern city.
The witness claimed that a fire crew extricated a man's dead body from the wreckage.
At least four persons were killed in at least two waves of airstrikes carried out by Russia on Kyiv and other cities on Monday.
The Russian strikes followed advances by Ukrainian forces in the east and south and after an Oct. 8, blast on a bridge linking mainland Russia to Crimea, the peninsula Russia annexed from Ukraine in 2014.
“Right now, there is a new Russian drone attack,’’ Zelenskiy, said in a Monday evening video address.
“There are (drones) that have been shot down.’’
The Interfax Ukraine news agency said Telegram users had reported a blasts in the town of Fastiv just outside Kyiv, as well as in the southern port of Odesa.
U.S. President Joe Biden’s press secretary Karine Jean-Pierre told reporters that the White House “strongly condemns Russia’s missile strikes’’ and said the attack continued to demonstrate Putin’s brutality’’.
Russian President, Valdimir Putin sent tens of thousands of troops into Ukraine on Feb. 24 in what he called a “special operation” to root out what it calls dangerous nationalists.
Ukrainian forces have mounted stiff resistance, with the help of arms supplied by the United States and its allies, who have also imposed sweeping sanctions on Russia in an effort to force it to withdraw.
Mentioning a $725 million military aid package announced for Ukraine last Friday, Jean-Pierre said the United States would stand with the people of Ukraine “for as long as it takes’’.
“We will continue to impose costs on Russia, hold them accountable for its war crimes,’’ she said.
Russia denies targeting civilians. Its defence ministry said it had carried out a “massive” attack on military targets and energy infrastructure across Ukraine using high-precision weapons.
Ukraine said the attacks were carried out by Iran-made “suicide drones”, which fly to their target and detonate.
The United States, Britain and France agreed that Iran supplying drones to Russia would violate a U.N. Security Council resolution that endorsed the 2015 nuclear deal between Iran and six powers.
Iran on Monday stuck to its denial that it is supplying the drones to Russia, while the Kremlin has not commented.
The White House accused Iran of lying when it says Iranian drones were not being used by Russia in Ukraine.
Asked for comment, the Iranian mission to the United Nations repeated a statement issued by the government on Friday that said it supports upholding the U.N. Charter and the U.N. attempts to find a peaceful solution to the conflict in Ukraine.
Several EU foreign ministers on Monday called for sanctions against Iran over the transfer of drones to Russia.
Ukraine’s military said it had destroyed 37 Russian drones since Sunday evening, or around 85 per cent of those used in attacks.
Reuters was not able to independently verify that tally.