A powerful explosion in a residential complex lobby in northeastern Moscow early Monday claimed the life of a pro-Kremlin paramilitary leader from eastern Ukraine, according to state media reports citing medical and law enforcement sources. Armen Sarkisyan, founder of the irregular Arbat Battalion, succumbed to his injuries after being hospitalized in critical condition, the state-run TASS news agency reported. Russia’s Investigative Committee, responsible for probing major crimes, later confirmed his death.