Ukraine's defence ministry said on Monday says Russian forces backed by tanks and artillery were conducting "storming operations" on the Azovstal steel plant in Mariupol where the city's last defenders are holed up.
Defence Ministry spokesman Oleksandr Motuzyanyk gave no further details but said, without providing evidence, that there could be future attacks by Russian bombers.
Russia has previously denied assertions by Ukrainian officials that it has tried to storm the sprawling plant on the Sea of Azov where civilians have also been sheltering.
