A general in charge of the Russian military’s nuclear and chemical weapons protection forces was killed by a bomb on a Moscow street on Tuesday, the Russian authorities said, in one of the most brazen assassinations since Russia’s full-scale invasion of Ukraine nearly three years ago.

The general, Igor Kirillov, died along with an aide after an explosive device planted in a scooter was detonated on Tuesday morning near the entrance to a residential building, Russia’s Investigative Committee, a law enforcement agency, said in a statement.

An official with Ukraine’s security service, known as the SBU, said that Ukraine was responsible for the killing. The official, who spoke on the condition of anonymity to discuss a sensitive intelligence operation, confirmed the details of the assassination given by Russia.

The SBU considered General Kirillov a legitimate target, the official said.

A day before his killing, the SBU had charged General Kirillov in absentia, saying he was responsible for the “massive use of banned chemical weapons” in Ukraine.

The division he oversaw carries out specialised tasks, including protecting Russian troops when chemical and nuclear weapons are used.

General Kirillov was also a player in Russia’s propaganda campaign against Ukraine and the West, frequently addressing the news media with unfounded claims. In 2023, for instance, he said that the US was planning to use drones “designed to spread infected mosquitoes”.

General Kirillov also claimed that Russian forces had uncovered a chemical weapons production laboratory near Avdiivka, a Ukrainian city that Moscow’s troops captured in February.

On Tuesday, the RIA Novosti state news agency published a photograph of what it said was a bomb-disposal robot operating outside a brick building in Moscow. The agency reported that the explosion occurred at about 6:12 am (local time) and was so powerful that it damaged windows as far up as the third floor and shattered them in a building across the street.

General Kirillov was the head of Russia’s radioactive, chemical and biological defence forces. He helped develop a thermobaric rocket launcher, the TOS-2, according to a biography published by RIA Novosti.

Dmitri Medvedev, a former President and deputy chairman of the Russian Security Council, on Tuesday blamed Kyiv for the killing, pledging “inevitable retaliation” against “military and political leadership of Ukraine.”

By assassinating General Kirillov, the Ukrainian government is trying to “drag out the war and killing” in Ukraine, Medvedev said in a statement issued by the security council, according to Tass.

The killing of General Kirillov was the highest-profile apparent assassination of a Russian military official far from the battlefield since the start of the invasion in 2022.