Russian authorities described bombing as ‘an act of terrorism’ and blamed Ukrainian intelligence agencies for orchestrating it.
The blogger, Vladlen Tatarsky, 40, was an ardent supporter of the war in Ukraine and filed regular reports on the fighting from the front lines.
He was killed on Sunday as he led a discussion at a riverside café in the historic heart of St Petersburg, Russia’s second-largest city.
Russian authorities described the bombing as “an act of terrorism” and blamed Ukrainian intelligence agencies for orchestrating it.
Police arrested 26-year-old St Petersburg resident Darya Trepova, who was seen on video moments before the blast presenting Tatarsky with a statuette that is believed to have contained explosives.
Russia’s health ministry said 42 others had been injured in the blast, and 24 were still in hospital as of late Tuesday.
The Ministry of Internal Affairs released a video in which Trepova told a police officer that she brought the bust to the café. When asked who gave it to her, she said she would explain later.
The National Anti-Terrorist Committee, which coordinates counterterrorism operations, said the bombing was “planned by Ukrainian special services”. It said Trepova was an “active supporter” of imprisoned Russian opposition leader Alexei Navalny.
Last year, she was arrested and spent 10 days in custody after taking part in an anti-war rally.
Ukrainian authorities did not directly respond to the accusation, but President Volodymyr Zelenskyy said in reference to the attack that he does not think about events in Russia, and his top adviser described the bombing as part of Russia’s internal turmoil.
While Trepova was arrested in St Petersburg, her case was sent to Moscow, where the country’s top investigative agencies are based, an apparent reflection of its high priority.
In a closed-door hearing on Tuesday, Moscow’s Basmanny District Court ordered Trepova to remain in custody until June 2 pending the investigation.
The Investigative Committee, which probes major crimes, said it had charged Trepova with committing “a terrorist act by an organised group that caused intentional death”.
Russian law suggests a life sentence for terrorism-related crimes, but life terms are not handed down to women, who instead face sentences of up to 20 years in prison.
Tatarsky was the pen name of Maxim Fomin, who had accumulated more than 560,000 followers on his Telegram channel.
Tatarsky, who joined separatists in eastern Ukraine after a Moscow-backed rebellion erupted there in 2014, fought on the front lines for years before turning to blogging.