Well-known Russian military blogger Vladlen Tatarsky was killed by a bomb blast in a St Petersburg cafe on Sunday in what appeared to be the second assassination on Russian soil of a figure closely associated with the war in Ukraine.
Russia's state Investigative Committee said 19 other people were wounded in the blast, and it had opened a murder investigation.
Tatarsky, whose real name was Maxim Fomin, had more than 560,000 followers on Telegram and was one of the most prominent of the influential military bloggers who have championed Russia's war effort in Ukraine while often criticizing the failures of the army top brass.
"We'll defeat everyone, we'll kill everyone, we'll rob everyone we need to. Everything will be as we like it," he was shown saying in a video clip last September at a Kremlin ceremony where President Vladimir Putin claimed four occupied regions of Ukraine as Russian territory - a move rejected as illegal by most countries.
There was no indication who was behind the blast.
Details of the Saint Petersburg blast
TASS news agency quoted an unnamed source as saying the improvised explosive device was hidden in a miniature statue that was handed to Tatarsky as he addressed a group of people in the cafe.
Mash, a Telegram channel with links to Russian law enforcement, posted a video that appeared to show Tatarsky, microphone in hand, being presented with a statuette of a helmeted soldier. It said the explosion happened minutes later.
Tatarsky's death followed the killing last August of Darya Dugina, the daughter of a prominent ultra-nationalist, in a car bomb attack near Moscow.
Russia's Federal Security Service accused Ukraine's secret services of carrying out that attack, which Putin called "evil." Ukraine denied involvement.
Russia's war bloggers, an assortment of military correspondents and freelance commentators with army backgrounds, have enjoyed broad freedom from the Kremlin to publish hard-hitting views on the war, now in its 14th month. Putin even made one of them a member of his human rights council last year.
They reacted with shock to the news of Tatarsky's death.
"He was in the hottest spots of the special military operation and he always came out alive. But the war found him in a Petersburg cafe," said Semyon Pegov, who blogs under the name War Gonzo.
Alexander Khodakovsky, a leading pro-Moscow figure in eastern Ukraine, wrote: "Max, if you were a nobody, you'd have died of 'vodka and head colds. But you were dangerous to them, you did your business like no one else could. We will pray for you, brother."