The killing of a senior Russian military official, Igor Kirillov, in Moscow on Tuesday was a “special operation” by Ukraine’s SBU security service, a source inside the agency told AFP.Kirillov is the most senior Russian army official to be targeted on Russian territory, killed with his assistant when an explosive device attached to a scooter went off outside an apartment building in south-eastern Moscow.For all the latest headlines follow our Google News channel online or via the app.“The liquidation of Lieutenant General Igor Kirillov, chief of the Russian Armed Forces’ radiation, chemical and biological defence troops is a special operation by the SBU,” the source said.“Kirillov was a war criminal and an absolutely legitimate target, as he gave orders to use banned chemical weapons against the Ukrainian military,” it said.Kirillov was on Monday charged in absentia by Ukrainian authorities over alleged war crimes following an investigation by the SBU.Russia denies those accusations.In