POKROVSK, Ukraine (AP) – Russia claims to have captured Mariupol in what would be its biggest victory yet in its war with Ukraine. A spokesman said the Russian defense minister reported the “complete liberation” of the Azovstal steel plant – the last stronghold of Ukrainian resistance – and the city as a whole. The announcement followed a nearly three-month siege that reduced much of the strategic port city to a smoking ruin. More than 20,000 civilians are feared dead. There was no immediate confirmation from Ukraine. A Russian state news agency quoted the ministry as saying that more than 2,400 Ukrainian fighters who had been holed up at the steelworks had surrendered since Monday, including over 500 on Friday.