Attacks have resumed on Mariupol's steel works, despite hundreds of civilians remaining trapped inside, a Ukrainian officer has said.
The Azovstal plant was being shelled by "all kinds of weapons", Ukraine's National Guard commander Denys Shlega said today.
Yesterday a number of civilians who had sheltered inside the last resistance stronghold managed to escape.
But "several dozen small children are still in the bunkers underneath the plant", the commander said.
The shelling on the plant in the southern port city, which has been under intense Russian bombardment for weeks, began as soon as the civilians who had been evacuated left, he told Ukrainian television.
On Monday evening (local time), footage emerged apparently showing a massive fire at the Azovstal, in what social media users said was a result of Russian bombardment.
A first group of evacuees from the steelworks were expected to arrive in the Ukrainian-controlled city of Zaporizhzhia yesterday but the rescue efforts have run into delays, BBC's Laura Bicker, who is in the city, reported.
It was not clear what is causing the hold-up, she said. The convoy was on its way, but the buses hade hundreds of miles to travel along a road which is - in part - rubble. They also had to go through a number of Russian checkpoints.
Those who left Mariupol yesterday were evacuated with the support of the United Nations (UN) and the International Committee of the Red Cross, which organised an official convoy.
Russia said some evacuees had been taken to a village controlled by Russian-speaking separatists.
Ukraine's President Volodymyr Zelensky welcomed the news that around 100 people were heading for Zaporizhzhia, about 230km north-west of Mariupol.
"Grateful to our team! Now they, together with UN, are working on the evacuation of other civilians from the plant," he wrote on Twitter
Some people have spent many weeks in the Azovstal steelworks, with reports suggesting food, water and medicine supplies are all running low.
"The situation has become a sign of a real humanitarian catastrophe," Ukraine's Deputy Prime Minister Iryna Vereshchuk said.
One Russian news report estimated the number of civilians still in the plant was more than 500.
A few evacuees from Mariupol who had not been trapped in the steelworks arrived in Zaporizhzhia earlier on Monday after travelling independently.
"We lived in [our] basement starting from 27 February," Natalya Tsyntomirska told Reuters news agency. "The whole time, we were shelled with mines, and then air strikes started. Our house is completely destroyed."
Another evacuee, who did not give a name, said she had been unable to reach the evacuation buses because of a blockade.
"Our city is divided between the left bank and right bank. The left bank was under a total blockade. We couldn't reach these buses," she said.
The Mariupol city council said an evacuation of civilians with the support of the UN and Red Cross had been agreed for Tuesday at 7am (local time).
Russia has so far made no public comments on the issue. A number of similar evacuation attempts have failed in recent days - with both Ukraine and Russia blaming each other for reneging on the agreed terms.
- BBC