Russia asserted Thursday that the claim from Ukraine that Moscow forces were responsible for the bombing of a maternity hospital in the port city of Mariupol was “fake news.”

“That’s how fake news is born,” Dmitry Polyanskiy, Russia’s first deputy permanent representative to the United Nations, said on Twitter.

He said that Russia had said in a statement on March 7 that the hospital in Mariupol “has been turned into a military object” from which Ukrainian radicals were firing.