Chilling vision has emerged of the moment a top Russian military leader in charge of chemical weapons was assassinated in Moscow.

Lieutenant General Igor Kirillov, chief of Russia's Nuclear, Biological and Chemical Protection Troops, was killed outside an apartment building.

General Kirillov, 54, died along with an aide after an explosive device planted in a scooter was detonated on Tuesday morning near the entryway to a residential building, Russia’s Investigative Committee, a law enforcement agency, said in a statement.