The Russian Investigative Committee said Lieutenant General Igor Kirillov was leaving a residential area on the morning of December 17 when an explosive device hidden in an electric scooter detonated. The explosion killed General Igor Kirillov and an assistant.
Lieutenant General Igor Kirillov was the head of Russia's Nuclear, Biological and Chemical Defense Forces (RChBD). He was killed outside an apartment building on Ryazansky Prospekt, about 7 km southeast of the Kremlin.
Photos posted on a Russian Telegram channel showed the entrance to a building in ruins after the explosion, with two bodies inside.
Russia's Investigative Committee said it had "opened a criminal case into the murder of two servicemen".
“Investigators, forensic experts and law enforcement are working at the scene. Investigations and search operations are underway to establish all the circumstances of the crime,” the agency said in a statement.
According to the BBC, in October this year, the UK imposed sanctions on General Kirillov for overseeing the use of chemical weapons in Ukraine.
On December 16, the Ukrainian secret service SBU charged General Kirillow in absentia with "responsibility for the mass use of banned chemical weapons".