Russia's state Investigative Committee said on Monday it was examining the alleged use of chemical weapons by Ukrainian forces near the eastern Ukrainian towns of Soledar and Bakhmut.
Ukraine's Armed Forces said they had never used chemical weapons anywhere at any time and accused Moscow of engaging in disinformation and of itself using banned weapons.
Russia's Investigative Committee said the Donetsk People's Republic, one of Russia's proxies in the territories it has seized and occupied, had reported the use of chemical weapons by Ukrainian drones near the two locations. The allegation was not accompanied by any publicly released evidence.
"As a result, servicemen of the Russian Armed Forces are experiencing a deterioration in their health and characteristic symptoms of poisoning," the committee said, without providing details or identifying any substance.
Ukraine's Armed Forces said they adhered to laws of war. "The enemy's accusations of the use of chemical weapons by units of the Armed Forces of Ukraine are untrue," the public affairs office said in an emailed statement. It went on to say Ukraine had never used such weapons "anywhere ... at any time."
Since the start of its invasion nearly a year ago, Russia has repeatedly warned that Ukraine might be preparing to use non-conventional weapons, including biological weapons or a radioactive dirty bomb. No such attack has materialised.
Ukraine and its Western allies rejected those accusations but saw them as a possible prelude to a "false flag" attack, meaning Russia might itself resort to such tactics but seek to blame Ukraine. Russia has dismissed that claim.
Ukraine's Armed Forces, in the statement, accused Russia of using "banned phosphorus and chloropicrin ammunition" and of using "disinformation as a weapon."
(Reporting by Reuters; editing by Guy Faulconbridge, Jon Boyle and Grant McCool)
