Horror conditions for hundreds of civilians ‘including 60 kids’ trapped in Mariupol bunker in desperate last stand

TERRIFIED civilians including dozens of kids remain trapped in horror conditions beneath a steel plant as brave Ukrainians stage a final stand against Russia in the besieged city of Mariupol.

Horrifying footage shared by solidiers holed up in a bunker under the Azovstal iron and steel works - the port city's last remaining holdout - shows mums and tots among those desperately waiting to be evacuated.

Mariupol has been battered by Russian troops ever since Vladimir Putin ordered his troops into Ukraine in February - with large parts of the city reduced to rubble by constant air and artillery pounding.

Troops defending Ukraine from the Ukrainian 36th Marine Brigade and the Azov Battalion are using tunnels underneath the steelworks to make a last stand against the Russians.

The plant has become the final refuge for hundreds of Ukrainians in Mariupol - including 60 children, according to Commander of Ukraine's 36th Separate Marine Brigade Major Serhiy Volyna 

But as the hero Ukrainian troops cling on to the final piece of Mariupol, the United Nations has been frantically brokering a civilian evacuation from the last Ukrainian stronghold in the bombed-out ruins of the city.

It's estimated around 100,000 civilians remain in the city - with 1,000 living beneath the sprawling Soviet-era steel plant, according to Ukrainian officials, as food and supplies run out.

Ukraine has not said how many fighters also are in the plant, the only part of Mariupol not occupied by Russian forces, but the Russians put the number at about 2,000.

Graphic videos and images shared from inside the plant purport to show kids holed up there while injured men need stained bandages changed as others have open wounds or amputated limbs.

A skeleton medical staff was treating at least 600 wounded people, two Ukrainian women who said their husbands are among the fighters refusing to surrender there told Associated Press.

Some of the wounds were rotting with gangrene, they said.

According to reports, some kids at the steel plant are losing their hair and teeth because of stress after watching their parents be killed.

A woman identified only as Viktoria told she has spoken to her brother, a national guard soldier sheltering in Azovstal, who has told her there are "many elderly and children" at the plant.

"Some (children) are losing hair and teeth," she said, adding that some have grown grey hairs and are starting to stutter.