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White, brightly glowing projectiles fall over the Azovstal steelworks in the Ukrainian port city of Mariupol.
Is this Russian shelling with phosphorus ammunition?
This burns up to 1300 degrees hot and causes severe skin injuries.
Alexander Kelle, chemical weapons expert at the University of Hamburg
"What I've seen in the video snippets on social media makes me suspect that we're dealing with thermite bombs and not phosphorus bombs."
Both phosphorus and thermite bombs start burning in mid-air and are often confused.
Alexander Kelle, chemical weapons expert at the University of Hamburg
“Phosphorus bombs, as the name suggests, use phosphorus, usually not to illuminate a battlefield, but to produce clouds of smoke.
With the thermite bombs, thermite is a metal-oxide mixture, which becomes welding, which means it burns through all sorts of materials very well.”
Which weapon was used in the end could probably only be clarified by an independent investigation.
Thermite weapons also inflict serious injuries on people.
The use of incendiary weapons is not strictly prohibited under international law, but it is outlawed and only permitted in a few exceptional cases.
In particular, they may not be used against civilians.
Alexander Kelle, chemical weapons expert at the University of Hamburg
»I would tend to think that it is a violation of international law because the restrictions under which such incendiary weapons can be used are very, very limited.«
According to Ukrainian sources, around 1,000 defenders of Mariupol have holed up in the steelworks, which has been besieged and shelled by the Russian army for weeks.
Around 600 are said to be injured, it was said recently.
They refuse Russian calls to surrender.