MOSCOW — An explosive device planted close to a residential apartment block in Moscow killed the head of Russia’s Nuclear, Biological, and Chemical Defence Forces, Lt. General Igor Kirillov, early Tuesday, Russia’s Investigative Committee said. [time-brightcove not-tgx=”true”] Kirillov’s assistant also died in the blast, triggered by the device which was placed in a scooter, officials said. The bomb was triggered remotely, Russian state news agency Tass reported, citing unnamed sources in the emergency services. Russian investigators have opened a case into the two deaths, according to the committee’s spokesperson Svetlana Petrenko. “Investigators, forensic experts and operational services are working at the scene,” she said in a statement.