The mayor of Mariupol said on Wednesday, 4, that heavy fighting was underway in the Azovstal steelworks, the last pocket of Ukrainian resistance in the port city.
Russian state TV showed images of smoke rising over Azovstal, soldiers on the streets of Mariupol in an industrial area, and artillery being fired into the Donetsk region -- images that cannot be independently verified by the Associated Press.
Ukrainian commanders said Russian forces backed by tanks began attacking the plant, which includes a maze of tunnels and bunkers spread over 11 square kilometers.
It was unclear how many Ukrainian fighters were hiding, but Russian officials said the number is about 2,000 in recent weeks, and 500 have been wounded.
A few hundred civilians remained at the plant, Ukrainian Deputy Prime Minister Iryna Vereshchuk said.
Getting a full picture of the battle raging in the east has been difficult because air strikes and artillery barrages have made it extremely dangerous for reporters to move around. Both Ukraine and the Moscow-backed rebels fighting in the east have also introduced strict restrictions on reporting from the combat zone.