A prominent pro-Russia separatist figure from Ukraine was killed after a bomb exploded on Monday inside a gated residence in Moscow, Russian news media said, in what appears to be another attack targeting opponents of Kyiv.
The figure, Armen Sarkisyan, the founder of a battalion fighting in eastern Ukraine, was pronounced dead in a Moscow hospital, Russian news media said, citing the country’s Investigative Committee, which typically handles high-profile crimes.
The Investigative Committee said earlier in a statement that four people had been taken to a hospital with injuries after a bomb exploded at the Scarlet Sails apartment complex. It said one person had been killed in the explosion.
The Russian media reports said that Mr. Sarkisyan had been taken to the hospital with injuries and had died there, and that his bodyguard had died at the scene.
The agency did not name any suspects. It was also not immediately clear if Mr. Sarkisyan had been a resident of the complex.
Ukrainian officials have not yet commented on the blast.
The explosion inside a building in an upscale neighborhood appeared to be another significant attack in Moscow, where a Russian general was killed in December by a bomb planted on a scooter in an assassination Ukraine claimed.
The general, Igor Kirillov, was in charge of the Russian military’s nuclear and chemical weapons protection forces. His assistant also died in the attack.
Mr. Sarkisyan was wanted in Ukraine on accusations of plotting killings and hiring thugs to harass antigovernment activists during protests in Kyiv, the Ukrainian capital, in 2014.
He later supported Russia’s invasion of eastern Ukraine in 2014 and most recently founded a battalion fighting alongside Russian forces in Ukraine.
Ivan Prikhodko, the mayor of the Russian-controlled town of Horlivka in eastern Ukraine, where Mr. Sarkisyan was originally from, referred in a Telegram post to the leader’s death, without providing details. He hailed Mr. Sarkisyan’s Arbat battalion for playing a “crucial role in ensuring security” in areas of Ukraine’s Donetsk region that Russia had captured.
Footage posted by Tass, a state-owned news agency, and other Russian media outlets from the scene of the explosion showed the glass doors of the entryway mangled and smashed.
Russian officials did not immediately say how an explosive was planted and detonated.
Dmitri S. Peskov, a Kremlin spokesman, on Monday had no comment on the blast and said that an official inquiry was underway.