Lieutenant General Igor Kirillov, the head of Russia’s Nuclear, Biological, and Chemical Protection Troops, was assassinated in Moscow on Tuesday morning in a high-profile attack claimed by Ukraine’s SBU intelligence service. The assassination marks the most senior Russian military officer to be killed inside Russia by Ukraine since the start of the conflict. Kirillov, 54, was killed along with his assistant when a bomb hidden in an electric scooter detonated as they stepped out of an apartment building on Ryazansky Prospekt in Moscow, the Russian Investigative Committee reported. A source within the SBU confirmed to Reuters that the agency was behind the assassination, describing it as the “liquidation” of the general. Unverified video footage circulating on social media showed two men leaving the building and a large explosion shortly afterward, with the bodies of the victims lying on the pavement.The attack is likely to prompt Russian authorities to review security measures for top military officials. Kirillov’s death follows a series of high-profile assassinations attributed to Ukraine on Russian soil, aimed at weakening morale and holding those responsible for alleged war crimes accountable. His killing is likely to escalate tensions, with Russian officials threatening retaliation. Former Russian president Dmitry Medvedev warned that Ukraine’s military and political leadership would face “imminent revenge.” Kirillov was accused by Ukraine of being involved in the use of chemical weapons against Ukrainian troops. Russia has denied these allegations, and Kirillov, who was married with two sons, had previously appeared on Russian state television defending the country’s actions and accusing Ukraine of violating nuclear safety protocols. In October, the UK imposed sanctions on Kirillov for his role in allegedly using chemical weapons, including the toxic agent chloropicrin on the battlefield. Kirillov was also charged in absentia by Ukrainian state prosecutors for the alleged use of banned chemical weapons, just a day before his assassination. His name appeared on the Myrotvorets (Peacemaker) database, a Ukrainian site listing individuals deemed enemies of the state. The website marked his photo with the word “Liquidated” after his death. The assassination is part of a broader pattern of targeted killings attributed to Ukraine, which includes the 2022 car bomb killing of nationalist ideologue Darya Dugina, the 2023 bombing of pro-war blogger Vladlen Tatarsky, and the shooting of a Russian submarine commander accused of war crimes. Kirillov’s unit, the RKhBZ, is responsible for operating in contaminated environments and protecting Russian forces in conditions of chemical, biological, and nuclear contamination. His death will likely have significant ramifications for Russian security operations in these specialized fields.