The announcement comes hours after Mariupol’s mayor said heavy fighting was taking place at the steelworks where the city’s last defenders and some civilians are holding out.

More than 300 civilians were evacuated from the ruined Ukrainian port city of Mariupol and the surrounding areas on Wednesday, the Red Cross has said.
This includes “several dozen civilians” who left the besieged Azovstal steel plant and reached Zaporizhzhia during a five-day safe passage operation, the charity said in a statement.
“We are relieved that more lives have been spared,” said Pascal Hundt, the ICRC’s head of delegation in Ukraine. “We welcome the renewed efforts of the parties with regards to safe passage operations. They remain crucial and urgent in light of the immense suffering of the civilians.”
Russian forces have begun storming the steel mill containing the last pocket of resistance in Mariupol.
In a video posted on Wednesday, Denys Prokopenko, commander of the Ukrainian Azov regiment, said the incursions had continued for a second day “and there are heavy, bloody battles”.
Azovstal remains one of the biggest hubs of Ukrainian military resistance and has been subjected to massive Russian aerial bombardments and shelling.
Russian state TV has shown smoke rising over Azovstal.
It comes as Russia’s military said it would open humanitarian corridors from the steel plant for the next three days to allow civilians to leave the facility.
In an online posting, the military said the corridors would be open from 8am to 6pm local time.
During this period Russian forces would cease any military activity and withdraw units to a safe distance, it said.
One woman said the assault began “as soon as we were brought out” of the plant in the besieged city.