Civilians in Mariupol, Ukraine are trapped in an underground bunker after bombings broke out in Ukraine. Sources say they will have to be dug out by hand.

Ukrainian President Volodymyr Zelensky said more civilians had been rescued from Mariupol, but Russia was shelling the Azovstal steel plant where an estimated 200 civilians were still in underground bunkers with little food or water.

Russian President Vladimir Putin said Russia was prepared to provide safe passage for the civilians but reiterated calls for Ukrainian forces inside to disarm.

Clinging on desperately, Ukrainian fighters have reported fierce battles with Russian troops. Putin declared victory over Mariupol on April 21 and ordered his forces to seal off the Soviet-era plant but not venture inside its underground tunnel network.

The Kremlin denies Ukrainian allegations that Russian troops stormed the plant in recent days. Ukraine’s stubborn defense of Azovstal has underlined Russia’s failure to take major cities in a 10-week-old war that has united Western powers in arming Kyiv and punishing Moscow with sanctions.

Russia’s military promised to pause its activity in Azovstal during the day on Thursday and the next two days to allow civilians to leave after fighting prevented evacuations from the plant on Wednesday.

The Kremlin said humanitarian corridors from the plant were in place. A Ukrainian fighter who said he was holed up in Azovstal accused Russian forces of breaching the plant’s defenses for a third day despite an earlier pledge by Moscow to pause military activity to permit civilian evacuations. Zelinsky says a truce is needed, until then, they are stuck.