Russian officials say they have arrested a suspect over the death of a pro-war military blogger killed in an explosion at a cafe in St Petersburg.

Around 30 people were also wounded in the explosion, with 10 of them said to be in a critical condition, according to the authorities.

Image: Daria Trepova

Tatarsky, 40, whose real name was Maxim Fomin, had more than 560,000 followers on Telegram.

He was one of the most prominent of the influential military bloggers, who have provided a running commentary on Russia's invasion of Ukraine.

Russian news reports said the bomb was hidden in a bust of the blogger that the suspect had given to him as a gift just before the blast.

Image: Vladlen Tatarsky. Pic: Telegram @Vladlentatarskybooks/via Reuters

Counter-terror officials in Russia have declared the incident a terror attack, which they claim was planned by Ukrainian special services and involved "collaborators" from the Navalny Anti-Corruption Foundation.

The non-profit group, which has investigated corruption among high-ranking Russian officials, was founded by opposition leader Alexei Navalny, who is currently serving a jail sentence in Russia for alleged fraud and contempt of court.

The National Anti-Terrorist Committee claim Trepova is an "active supporter" of the group, which has previously been declared a "foreign agent" and banned in Russia.

On Monday, the Russian Ministry of Internal Affairs released a video of Trepova which appears to show a confession.

Image: On Monday, the Russian Ministry of Internal Affairs released a video of Trepova which appears to show a confession. The circumstances under which the filming was done are not known

Russia has announced it will tighten security at its upcoming Victory Day celebrations in May - a highly significant day on the Russian calendar.

Tatarsky was killed as he led a discussion at a cafe on the banks of the Neva River in the historic heart of St Petersburg.

In remarks recorded on video, a witness said that a woman who identified herself as Nastya asked questions and exchanged remarks with Tatarsky at the event.

The witness, Alisa Smotrova, quoted Nastya as saying she had made a bust of the blogger but that guards asked her to leave it at the door, suspecting it could be a bomb.

Who is Daria Trepova?

The woman arrested over the death of military blogger Vladlen Tatarsky is a 26-year-old who has previously been detained for taking part in anti-war rallies.

Russia's Investigative Committee - the country's top state criminal investigation agency - says it has arrested Daria Trepova over the 40-year-old's death.

Investigators believe the bomb used to kill Tatarsky was hidden in a bust of the blogger that the suspect had given to him as a gift just before the explosion.

Some media reports suggested that Trepova could have been unaware that the bust contained an explosive device and was used by those who staged the attack to deliver it.

Russia's interior ministry had put Trepova on the wanted list on Monday. The country's National Anti-Terrorist Committee claim she is an "active supporter" of the Navalny Anti-Corruption Foundation, which has previously been declared a "foreign agent" and banned in Russia.

Trepova is said to have been detained at a property in St Petersburg.

Nastya and Tatarsky joked and laughed. She then went to the door, grabbed the bust and presented it to Tatarsky.

He reportedly put the bust on a nearby table, and the explosion followed. Ms Smotrova described people running in panic, some hurt by shattered glass and covered in blood.

A St Petersburg website said the cafe had at one time belonged to Yevgeny Prigozhin, founder of the Wagner Group - the private army that is fighting for Russia in Ukraine.

Image: Police officers stand guard at the scene of the cafe explosion in which Russian military blogger Vladlen Tatarsky was killed

A leading Russian official blamed Ukraine for the attack, without providing evidence. The claim was rebuffed by Kyiv.

Mykhailo Podolyak, a Ukrainian presidential adviser, blamed Russian domestic terrorism for the blast.

Darya Dugina, the daughter of a Vladimir Putin ally, was killed last August after a suspected explosive device detonated on the Toyota Land Cruiser she was travelling in.

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Fatal explosion at St Petersburg cafe

Tatarsky was among hundreds of attendees at a lavish Kremlin ceremony last September to proclaim Russia's annexation of four partly occupied regions of Ukraine.

"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.

Military analyst Sean Bell told Sky News it "looks really unlikely" that the Ukrainian military was behind the St Petersburg attack as it wasn't a military target.

"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.