Russia has moved nearer to taking control over Ukraine’s Donbas region, claiming victory in the monthslong battle for Mariupol’s Azovstal steel plant while launching a major offensive in the eastern Luhansk region.

The last Ukrainian forces holed up in the Azovstal steelworks surrendered on May 20, Russia’s Defense Ministry said.

It came after a devastating siege that has left Mariupol in complete ruins, with some 20,000 feared dead.

“The underground facilities of the enterprise, where the militants were hiding, came under the full control of the Russian armed forces,” the ministry said in a statement.

It said 531 people were in the group that gave up most recently and that brought to 2,439 the total number of defenders who had surrendered in the past few days.

There was no immediate confirmation from Ukraine, but President Volodymyr Zelenskiy said earlier than the Azovstal defenders got a clear signal from military command that they could get out and save their lives.