RUSSIA has been accused of pummeling Ukrainian defenders at the Mariupol steel plant with 2,500C deadly phosphorus bombs.
Hundreds of soldiers remain holed up at the bomb-blitzed site as they stage a desperate final stand against Putin's troops in the besieged city.
Horror aerial footage shows a Russian missile detonating mid-air above the devastated plant.
Flaming explosives can then be seen raining down onto the blitzed site.
The relentless fiery bursts - groupings of incendiary munitions - then explode as they hit the ground and buildings.
Ukrainian officials claim the clip shows Russian forces dropping 9M22S incendiary and phosphorus bombs on the steelworks - which combust at up to 2,500C.
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White phosphorous causes injuries and death by burning deep into tissue, through being inhaled as a smoke and by being ingested.
Mykhailo Fedorov, Ukraine's vice prime minister, tweeted: "Video evidence of possible usage of phosphorus bombs against defenders of Mariupol.
"Azovstal stands not only for Ukraine, but for the whole Europe.
"The bravest humankind. Never forgive, never forget."
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Russia was previously accused of using deadly phosphorous bombs in Ukraine after footage emerged showing what was alleged to be white phosphorous burning fiercely on the ground in the eastern city of Kramatorsk.
Separate images showed it apparently glowing in the sky above Kyiv.
Civilians sheltering at the steel plant were this month evacuated, with hundreds of soldiers remaining in the network of tunnels beneath the site.
Earlier this month, shocking footage showed the moment huge explosions ripped through the plant as Russian forces blasted the site with thermobaric missiles.
It comes after Kalush Orchestra frontman Oleg Psiuk implored people to help free hundreds of Ukrainian fighters trapped in the steel mill during the Eurovision song contest.
The Azov battalion, which is among the plant's last 1,000 defenders, sent their thanks from the warren of tunnels beneath the plant.
They posted on Telegram: "Thank you to Kalush Orchestra for your support! Glory to Ukraine!"
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But in a chilling response, Russian troops reportedly wrote "Kalush, as you asked", "help Mariupol" and "help Azovstal right now" across a bomb.
Haunting pictures published Pro-Kremlin Telegram channels show the hashtag Eurovision2022 written across a bomb as well as references to Kalush Orchestra, Ukraine's victorious band.