Ukrainian soldiers are running low on anaesthetic for a make-shift clinic inside their country's last outpost in Mariupol.
Despite relentless ground and air assaults from the Russian forces, the Ukrainian troops stuck inside the Azovstal steel plant are refusing to surrender.
With many of the fearsome Azov Battalion among their number, what's left of the Ukrainian army in the southern port city has managed to launch counteroffensives against the Russians and hold their defensive line despite the overwhelming odds against them.
It is unclear how many civilians and soldiers remain alive and within the steel plant, which is owned by the country's richest man Rinat Akhmetov.
According to Major Serhiy Volyna of the 36th Separate Marine Brigade, who is in Azovstal, 500 soldiers are wounded.
He said the situation inside had quickly become "critical" and "tragic", and many of the wounded were being left to "rot" in the basement as supplies of medicine run out.
Another army officer, speaking to the New York Times, painted a similarly bleak picture.
"They're taking colossal losses. they won't say how many people are left alive, but they do have more than 500 wounded," reporter Michael Shwirtz said.
"One of the troops took a short video of their clinic. It's a gruesome scene with a lot of troops in there with absolutely ghastly injuries.
"They don't have medicines, they're running low on anaesthesia.
"They're having to conduct amputations in really disastrous conditions. It is pretty grim inside.
"They say they want the outside world to help, but there is an acknowledgement there is very little that can be done."
Russian forces attempted to storm the steel plant on Sunday, Ukrainian officials said, despite President Vladimir Putin claiming the complex did not need to be taken last week.
Ukraine's armed forces command wrote on Facebook that Russians were firing and performing "offensive operations" in the Azovstal area, as well as conducting air strikes on civilian infrastructure.
Konstantin Ivaschenko, the official who has been designated mayor of Mariupol by Russia but not recognised as such by Ukraine, denied that any fighting was taking place in the city in comments reported by Russian news outlet TASS on Sunday.
Earlier on Sunday, Ukrainian presidential adviser Oleksiy Arestovych wrote on Facebook that "Russian troops are trying to finish off the defenders of Azovstal and more than 1,000 civilians who are hiding at the plant".
Russia has denied targeting civilians in what it calls a "special military operation" to demilitarise and "denazify" Ukraine, with many pro-Russian supporters of the war claiming that troops stuck inside the plant are using human shields.
Ukrainian officials have denied Russian claims that a safe route out of the steelworks has been provided.
If the defending forces were to surrender, they would be taken as prisoners of war, Russia has claimed.
It is unclear what would happen to the civilians stuck inside.
Video taken from inside the factory by the Azov Battalion shows a number of children hidden several stories underground.
The basement room is filled with the belongings of those living there, who are wrapped in several layers of clothes to keep the cold out.
The steel plant has been under constant bombardment for weeks, with Russian ships hammering it with shells from the Azov Sea.
Drone footage released at the end of last week shows how badly damaged the vast complex has become.
Smoke can be seen rising from the metal work's towers while the shells of gutted out buildings stand in ruin and rubble.
Russia’s defence ministry had said on Monday that it would open a humanitarian corridor for civilians to leave the huge Azovstal steel plant where they are holed up with Ukrainian fighters and are under Russian attack.
In response on Monday, Ukrainian Deputy Prime Minister Iryna Vereshchuk wrote on the Telegram messaging app: “Today, the Russian side once again announced the existence of a corridor for civilians to leave Azovstal. This could be believed if the Russians had not destroyed humanitarian corridors many times before.
“It is important to understand that a humanitarian corridor opens by the agreement of both sides. A corridor announced unilaterally does not provide security, and therefore is not a humanitarian corridor.”
Separately, Ukrainian presidential aide Oleksiy Arestovych said Russian forces were continuing to attack the steelworks on Monday.
“The enemy continues to attack our defences in the area of the Azovstal plant, using aircraft, artillery … firing with tanks and trying to advance with assault groups, violating the order of their own supreme commander,” Arestovych said in a video address.
