Lieutenant General Igor Kirillov, the head of the Russian Armed Forces' radiation, chemical, and biological defense troops, was killed in Moscow on Dec. 17 in an operation of the Security Service of Ukraine (SBU), a source in the agency told the Kyiv Independent.
Kirillov and another Russian service member were reportedly killed in an explosion on the morning of Dec. 17 in the Russian capital. Ukrainian prosecutors previously charged the commander with using banned chemical weapons in the war against Ukraine.
According to the source, explosives attached to a scooter detonated when Kirillov and his aide approached the entrance of the house on Ryazansky Prospect in Moscow.
The Kyiv Independent could not verify the claims.
"Kirillov was a war criminal and completely legitimate target, as he gave orders to use banned chemical weapons against Ukrainian soldiers," the source said.
"Retribution for war crimes is inevitable."
According to the Mash Telegram channel, the explosion occurred at around 6 a.m. local time when a service car arrived for Kirillov. The pro-state outlet Kommersant reported that the general and his aide were killed by a homemade explosive device of around 300 grams of a TNT equivalent.
Russia's Investigative Committee began investigating the case as terrorism. Two undisclosed sources told the Russian RBC news agency that the investigators consider Ukraine's involvement the most likely scenario.
Moscow's forces have been increasingly deploying gas attacks against Ukrainian troops, a Kyiv Independent investigation from August showed. Ukrainian soldiers and officers interviewed by the Kyiv Independent acknowledged that the tactic is effective, allowing Moscow to capture positions occasionally without destroying them.
In October, the U.K. issued sanctions against Kirillov and his unit over the use of chemical weapons on the battlefield in Ukraine. The officer held senior positions within the radiation, chemical, and biological defense troops since 2012 and was appointed the department's chief in 2017, Meduza reports.