Ukraine’s Azov battalion reported that Russian forces conducted a chemical attack in the besieged city of Mariupol on April 11.
As of yet, Kyiv and the West have not confirmed the attack.
The battalion, which has been defending the city against the Russian invasion for over a month, released a message on Telegram.
“About an hour ago, the Russian occupation forces used a poisonous substance of unknown origin against the Ukrainian military and civilians in the city of Mariupol, which was dropped from an enemy UAV (unmanned aerial vehicle). The victims have respiratory failure, vestibular-atactic syndrome”.
Azov followed up with a video from Mariupol on April 12, in which the soldiers describe the attack. They assert that it was not close to populated areas and therefore “the contact with the substance was minimum”.
Nevertheless, the victims of the attack are reportedly suffering from hyperemia, high blood pressure, dryness and inflammation of the throat, and mucous membranes of the eye. Azov soldiers say they are providing medical care to the victims.
Speaking to those affected by the attack, including civilians, one man described seeing a fog “like smoke but not thick” before feeling short of breath.
Another described a “white smoke” and a “sweet taste”, which caused him to collapse.
Azov says that it is hard to analyse the substance at this time as they are in a complete blockade and under Russian fire.
They continue by claiming that Mariupol suffers regularly from “aircraft, navy, heavy flamethrower systems, artillery and phosphorus munitions”.
Aside from Azov’s reports, there is little evidence to confirm a chemical attack, leading to accusations that Azov is spreading disinformation.
However, the deputy mayor of Mariupol, Sergei Orlov, told the BBC that the city council had confirmed "chemical poisoning" from a Russian drone.
"We cannot provide more detailed information," said Orlov. "But we have confirmation from the military that this has happened."
Elliot Higgins, the founder of investigative platform Bellingcat, wrote on Twitter that proving the chemical attack will be hard. He stated that the most solid evidence would be collecting munition remains from the site of impact.
"If this is a chemical weapon then there should be remains of the munition, as they're designed to release chemical agents, not be blown to bits," Higgins tweeted.
Ukraine’s Deputy Defence Minister Anna Malyar announced that information is still being verified, and the use of chemical weapons has not yet been confirmed, but preliminary data suggests phosphorus munition was used.
Hours before the incident was reported, Eduard Basurin, the defence spokesman for the self-proclaimed Donetsk People’s Republic, advocated the use of “chemical troops” against the last Ukrainian forces in Mariupol.
In a televised interview, the spokesman said: “They'll find a way to smoke these moles out of their holes”.
Basurin has since denied that Russia conducted a chemical attack in Mariupol in an interview with Interfax on April 12, AP reports.
President Volodymyr Zelenskiy responded to Basurin’s threat of chemical weapons, saying Ukraine has taken this “very seriously”, but did not confirm that they had already been used, during a video address on April 11.
In response to the threat of chemical weapons, the Ukrainian leader called for a “much more severe and faster” reaction from the West. He particularly emphasised that in the next round of EU sanctions, “an oil embargo against Russia is obligatory”. He also asked for more weapons to “end this war faster”.
The reports of the chemical attack in Mariupol are being taken seriously by the US and UK, who have expressed concern this signals a new escalation in the war.
Both countries said they are looking into the alleged incident, reported the BBC.
US President Joe Biden stated last month that should Russia use chemical weapons, Nato will respond.
Russian forces previously hit a chemical tank containing nitric acid in the Luhansk region, which risked poisoning thousands of residents. However, this was not regarded as a chemical weapons attack.
Mariupol has suffered some of the worse fighting in the war, with 90% of infrastructure damaged, according to the mayor, Vadym Boichenko.
More and more Ukrainian troops in Mariupol are reportedly surrendering as Russia tightens its grip, having cut the city off from supplies for over a month.