An explosion in a cafe in St Petersburg on Sunday has killed well-known Russian military blogger Vladlen Tatarsky, local news agencies reported.
Sources were quoted as saying it was caused by an explosive device.
The blogger, whose real name was Maxim Fomin, had more than 560,000 followers on Telegram and was one of the most prominent military bloggers who have provided an often critical running commentary on Russia's war in Ukraine.
Last year, he was among hundreds of attendees at a lavish Kremlin ceremony to proclaim Russia's annexation of four partly occupied regions of Ukraine, a move that most countries at the UN condemned as illegal.
"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 on that occasion.
A St Petersburg website said the explosion took place at a cafe that had at one time belonged to Yevgeny Prigozhin, founder of the Wagner private army that is fighting for Russia in Ukraine.
RIA news agency said six other people were injured in the blast. There was no indication who was responsible.
If Mr Tatarsky was deliberately targeted, it would be the second assassination on Russian soil of a figure associated with the war in Ukraine.
Russia's Federal Security Service accused Ukraine's secret services last August of killing Darya Dugina, the daughter of an ultranationalist, in a car bomb attack near Moscow that President Vladimir Putin called “evil”. Ukraine denied involvement.
