Shocking claims about Russian chemical attack: 'Callous escalation'

Unconfirmed reports suggest Russian forces used chemical weapons in an attack against troops in the besieged port city of Mariupol in Ukraine.

The reports come from claims made by Ukraine’s right-wing Azov volunteer regiment.

The battalion leader, Andriy Biletsky, claimed three people are showing signs of chemical poisoning, according to the Kyiv Independent.

Ukraine's parliament said on Twitter Russian troops were firing nitric acid in the Donetsk region, where Mariupol sits.

"This was reported by the patrol police. Locals are urged to prepare protective face masks soaked in soda solution," the parliament tweeted.

Kyiv Independent reported the chemical substance was distributed through a drone.

Petro Andryushchenko, an aide to the mayor of Mariupol, wrote on his Telegram channel reports about a chemical attack had not been confirmed and that he expected to provide details and clarifications later.

'Deeply concerning' if reports are true

Australian officials are working to confirm reports of the attack, Foreign Minister Marise Payne says the reports are extremely concerning.

"If they are confirmed that will be a further wholesale breach of international law," Senator Payne told reporters in Sydney on Tuesday.

"(It's) a further indication of President Putin and Russia's absolute violation of every single value and every aspect of the rules-based global order which has stood us in such good stead for so many decades now."

British foreign secretary Liz Truss acknowledged the unverified claims on Twitter, saying the UK is working to verify details.

"Any use of such weapons would be a callous escalation in this conflict and we will hold Putin and his regime to account," she said.

Pentagon Press Secretary John Kirby said the US was aware of the reports of the potential attack, though according to CNBC, he said he could not confirm reports.

“These reports, if true, are deeply concerning and reflective of concerns that we have had about Russia’s potential to use a variety of riot control agents, including tear gas mixed with chemical agents, in Ukraine,” Kirby reportedly said.

On Monday, Ukrainian President Volodymyr Zelensky warned Russia could use chemical weapons in Ukraine.

• 'KILL THEM ALL': Radio orders for Russian soldiers intercepted

• Heartbreaking detail in gruesome photo from Ukraine massacre

• Heartbreaking story behind writing on Ukrainian toddler's back

He did not confirm whether chemical weapons had been used and he encouraged leaders around the world to impose strong sanctions on Moscow that would deter even talk of the use of such weapons.

"We treat this with the utmost seriousness," he said.

"I would like to remind world leaders that the possible use of chemical weapons by the Russian military has already been discussed. And already at that time it meant that it was necessary to react to the Russian aggression much harsher and faster."

Chilling threat hours before alleged chemical attack

Just hours before the alleged attack in Mariupol on April 11, Eduard Basurin, a spokesperson for Russian separatist forces in Donetsk, referenced using chemical weapons.

The statement was made with regards to the Azovstal steel mill, which Russian forces are trying to capture.

“There are underground floors (at Azovstal), and that’s why it makes no sense to storm this object now,” Basurin said according to the Kyiv Independent.

“We could have a lot of our soldiers killed, and the enemy won’t suffer casualties. That’s why currently we should figure out how to block this mill and find all ways in and out.

"And after that we should ask our chemical forces to find a way to smoke these moles out of their holes.”

It appears the comments were made on a Russian news site.

People were angered by the remarks, particularly in the wake of the potential chemical attack.

"You can already feel free to change Z to a real swastika. Openly switched to the methods of the Nazis," one person said on Twitter while sharing a clip of the interview with Basurin.

Do you have a story tip? Email: newsroomau@yahoonews.com.

You can also follow us on Facebook, Instagram, TikTok and Twitter and download the Yahoo News app from the App Store or Google Play.