(AP) — Russia’s top counterterrorism agency said Monday that the bombing attack that killed a well-known Russian military blogger was staged by Ukrainian security agencies.

Russian officials said Vladlen Tatarsky, 40, was killed Sunday as he was leading a discussion at a cafe on the banks of the Neva River in the historic heart of St. Petersburg. Over 30 people were wounded by the blast, and 10 of them remain in grave condition, according to the authorities.

The National Anti-Terrorist Committee, a state structure that coordinates counterterrorism, said that the attack on Tatarsky was “planned by Ukrainian special services” with the involvement of people who have cooperated with an anti-corruption foundation created by jailed Russian opposition leader Alexei Navalny. It noted that the arrested suspect was an “active supporter” of Navalny’s group.

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

Russia’s Investigative Committee, the top state criminal investigation agency, said that Darya Tryopova was arrested on suspicion of involvement in Tatarsky’s killing. Tryopova is a 26-year-old St. Petersburg resident who had been previously detained for taking part in anti-war rallies.

The Interfax news agency initially reported her arrest late Sunday, but later said that she was on the run while her mother and sister were summoned for questioning. Some media reports suggested that Tryopova could have been unaware that the bust contained an explosive device and was used by those who staged the attack to deliver it.

Witnesses said that the suspect asked questions and exchanged remarks with Tatarsky during the discussion. One witness said the woman told Tatarsky that 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. They joked and laughed, and then she went to the door, grabbed the bust and presented it to Tatarsky.

A video showed Tatarsky making jokes about the bust and putting it on the table next to him just before the explosion.

Russia’s Investigative Committee, the state’s top criminal investigation agency, opened a probe on charges of murder.

No one publicly claimed responsibility, but military bloggers and patriotic commentators immediately blamed Ukraine for the attack and compared the bombing to last August’s assassination of nationalist TV commentator Darya Dugina, who was killed when a remotely controlled explosive device planted in her SUV blew up as she was driving on the outskirts of Moscow.

Russian authorities blamed Ukraine’s military intelligence for Dugina’s death, but Kyiv denied involvement.

Dugina’s father, Alexander Dugin, a nationalist philosopher and political theorist who strongly supports the invasion of Ukraine, hailed Tatarsky as an “immortal” hero who died to save the Russian people.

Reacting to Tatarsky’s death, Russian Foreign Ministry spokeswoman Maria Zakharova said his activities “have won him the hatred of the Kyiv regime” and noted that he and other Russian military bloggers have long faced Ukrainian threats.

Yevgeny Prigozhin, the Russian millionaire owner of the Wagner Group military contractor spearheading Moscow’s offensive in eastern Ukraine, said he owned the cafe and handed it over to a patriotic group for meetings. He said he doubts the Ukrainian authorities’ involvement in the bombing, saying the attack was likely launched by a “group of radicals” unrelated to the government in Kyiv.

Since the fighting in Ukraine began Feb. 24, 2022, Ukrainian authorities have refrained from claiming responsibility for various fires, explosions and apparent assassinations in Russia. At the same time, officials in Kyiv have jubilantly greeted such events and insisted on Ukraine’s right to launch attacks in Russia.

A top Ukrainian government official cast the explosion that killed Tatarsky as part of internal turmoil.

“Spiders are eating each other in a jar,” Ukrainian presidential adviser Mykhailo Podolyak wrote in English on Twitter late Sunday. “Question of when domestic terrorism would become an instrument of internal political fight was a matter of time.”

Tatarsky, who had filed regular reports from Ukraine, was the pen name for Maxim Fomin, who had accumulated more than 560,000 followers on his Telegram messaging app channel.

Born in the Donbas, Ukraine’s industrial heartland, Tatarsky worked as a coal miner before starting a furniture business. When he ran into financial difficulties, he robbed a bank and was sentenced to prison. He fled from custody after a Russia-backed separatist rebellion engulfed the Donbas in 2014, weeks after Moscow’s annexation of Ukraine’s Crimean Peninsula. Then he joined separatist rebels and fought on the front line before turning to blogging.