Russia has branded the Ukrainian claims that it carried out the horrific bombing of a children's hospital in Mariupol as "fake news" saying the building was no longer a maternity hospital and that it had long been taken over by troops.
"That's how fake news is born," Dmitry Polyanskiy, Russia's first deputy permanent representative to the United Nations, said on Twitter.
Polyanskiy said Russia had warned on March 7 that the hospital had been turned into a military object from which Ukrainians were firing.
Ukrainian President Volodymyr Zelenskiy accused Russia of carrying out genocide after Ukrainian officials said Russian aircraft bombed the children's hospital on Wednesday.
Pregnant women and children may still be trapped under the wreckage after the Russian bombing with rescuers carrying out desperate searches throughout the night.
Want all the latest news and analysis from Ukraine? Sign up to our World News Bulletin here
Ukraine officials have said that at least 17 people have been injured by the shelling that saw heavily pregnant women among the people brought out of the destroyed hospital on stretchers.
UK Prime Minister Boris Johnson condemned the attack as “depraved”.
He said: “There are few things more depraved than targeting the vulnerable and defenceless.”
The White House also said the hospital bombing was a "barbaric use of military force to go after innocent civilians".
Russian officials had earlier pledged to halt firing so at least some trapped civilians could escape the port city, where hundreds of thousands have been sheltering without water or power for more than a week.
Both sides blamed the other for the failure of the evacuation.
"What kind of country is this, the Russian Federation, which is afraid of hospitals, is afraid of maternity hospitals, and destroys them?" Zelenskiy said in a televised address late on Wednesday.
Zelenskiy repeated his call for the West to tighten sanctions on Russia "so that they sit down at the negotiating table and end this brutal war".
The bombing of the children's hospital, he said, was "proof that a genocide of Ukrainians is taking place".
Ukraine's foreign ministry posted video footage of what it said was the hospital showing holes where windows should have been in a three-storey building. Huge piles of smouldering rubble littered the scene.
Among the more than two million refugees to have fled Ukraine, the United Nations Children's Fund (UNICEF) has said that more than half have been children.
At least 37 had been killed and 50 injured, it added.
The International Committee of the Red Cross said houses had been destroyed all across Ukraine.
"Hundreds of thousands of people have no food, no water, no heat, no electricity and no medical care," it said.
But Kremlin spokesman Dmitry Peskov, said: "Russian forces do not fire on civilian targets."
Russia calls its incursion a "special operation" to disarm its neighbour and dislodge leaders it calls "neo-Nazis."
