As Russian forces step up their assault on Mariupol's Azovstal steelworks, video appears to show some of the women and children trapped inside.
The video was released by the Azov battalion, which is one of the Ukrainian military units still holding the area in the face of heavy Russian air strikes.
The footage shows uniformed soldiers handing out food to civilians who appear to be crowded into an underground shelter.
A woman holding a toddler says people in the plant are running out of food.
A boy says he is desperate to get out after being in the plant for two months.
When our houses are rebuilt, we can live in peace. The date is April 21 according to some people speaking in the video.
The video shows some women wearing uniforms with the Azovstal insignia.
On Saturday Ukrainian presidential adviser Oleksiy Arestovych said Russian forces were hitting the Azovstal complex with air strikes and trying to storm it.
Moscow said earlier this week that it would not attempt to take it and would blockade the plant.
More than 1,000 civilians are in the plant along with troops defending it, according to Ukrainian authorities.
One woman said she had been in the steelworks since February 27, just days after Russia launched its invasion of Ukraine.
We are relatives of the workers. She said that this seemed to be the safest place at the time we came here when our house came under fire and became uninhabitable.
There are fears that more than 20,000 people have been killed in the siege of Mariupol so far.
An aide to Mariupol's mayor said that a new attempt to evacuate civilians failed on Saturday.
The giant Azovstal plant is the last holdout of Ukrainian defenders of the southern port city.
The Azov battalion, which has played a prominent role in the defence of Mariupol, was set up in 2014 by Ukrainian far-right nationalists and later incorporated as a regiment in Ukraine's national guard. Its current commanders have denied any links to the unit's former far-right ideology.