Igor Kirillov, a prominent Russian lieutenant general and the chief of radiation, chemical, and biological defense troops of the Russian Federation, was killed Tuesday in an explosion in Moscow. 

Kirillov and an assistant died after an explosive device attached to a scooter exploded outside a residential building. Ukraine’s security service, the SBU, has claimed responsibility. 

The SBU accused Kirillov of responsibility for “the massive use of banned chemical weapons,” alleging that Russia used ammunition coated with toxic compounds. Russia has denied these allegations.

Earlier this year, Kirillov alleged that Russian forces had found a Ukrainian chemical laboratory for the production of toxic substances in the city of Avdiivka. 

The Organization for the Prohibition of Chemical Weapons stated in May that allegations of chemical weapons use in the Russia–Ukraine conflict are “insufficiently substantiated.”

The Russian media has also confirmed the death of Kirillov and his assistant, reporting that their bodies were removed from the site of the explosion near a seven-story residential building on Ryazansky Prospect. 

The former President Dimitri Medvedev, currently the deputy chairman of Russia’s security council, also commented on Kirillov’s assassination. “Today, as a result of a terrorist act, our colleague and comrade was killed,” said Medvedev. “Law enforcement must find the murderers in Russia.” Medvedev also pledged “inevitable retaliation.”