Police in<a href="https://www.thenationalnews.com/tags/russia/" target="_blank"> Russia </a>on Monday arrested a prominent anti-war activist on suspicion of killing a military blogger in a bombing in <a href="https://www.thenationalnews.com/tags/st-petersburg/" target="_blank">St Petersburg.</a> Darya Trepova, 26, was detained by officers after Sunday's blast in a cafe that killed Vladlen Tatarsky and injured over 30 others. RT, the Russian state-controlled television channel, published a photo that appeared to show the suspect handcuffed to pipes connected to a radiator. Russia accused Ukraine of organising the murder. A police video showed a woman admitting planting the bomb. The Russian interior ministry published a video purportedly of Ms Trepova admitting to bringing a statuette that exploded to the cafe, and saying she understood the reasons for her arrest. When asked why, she said: "For... I'd put it this way, for being at the assassination site of Vladlen Tatarsky." "I brought the statuette there that exploded," she added. Asked on camera who gave it to her, she said she would answer "later". A separate video taken from CCTV shows a woman dressed in a long black coat and black boots walking into the cafe carrying a box. Another unverified clip released on Russian media appeared to feature the blogger showing what seemed to be a bust of the blogger to onlookers seated at tables. Alisa Smotrova, who was in the cafe at the time of the blast, described the attack. "They put (the figurine) somewhere in the back without a second thought... and all of a sudden there was an explosion," she told AFP. "There was blood and pieces of glass." The police were called at around 6:13 pm local time on Sunday and cordoned off the street outside the building. The blogger, 40, whose real name was Maxim Fomin, had more than 560,000 followers on Telegram and was one of the most prominent pro-war commentators in Russia. The Kremlin called the assassination a “terrorist act” and cited Russia's Anti-Terrorism Committee in saying that there was evidence linking Ukraine to the bombing. Kremlin spokesman Dmitry Peskov said: “The active phase of the investigation is now under way. “We see quite vigorous steps to detain suspects. Let's be patient and wait for the next announcements from our special services, which are working on this.” Russian anti-terrorism investigators accused Ukraine's security services and “agents” linked to opposition leader Alexei Navalny of being behind the attack. “The terrorist attack was planned by Ukrainian security services with the help of agents working with the so-called Anti-Corruption Foundation,” Russia's anti-terror committee said, referring to Mr Navalny's organisation. Mr Navalny, who survived a poisoning in August 2020 that he and western governments blamed on the Kremlin, is serving a nine-year prison sentence in Russia after being convicted of fraud and contempt of court. Russia dubbed his foundation “extremist” in 2021 and outlawed the organisation, after it published investigative reports about alleged corruption among top officials. The move was part of a Kremlin crackdown on staunch critics of President Vladimir Putin. Ukrainian presidential aide Mykhaylo Podolyak said the cafe attack happened as a result of Russian infighting. "(The) question of when domestic terrorism would become an instrument of internal political fight was a matter of time," he wrote on Twitter. Before the arrest of Ms Trepova, the Russian Interior Ministry had identified her as a suspect and she was placed on a wanted list. The campaigner, who lives in St Petersburg, was detained for 10 days for taking part in an anti-war protest on February 25, 2022, Russian state-run news agency RIA Novosti reported. The rally was held a day after Moscow invaded Ukraine. Mr Tatarsky was born in the Donbas, eastern Ukraine’s industrial heartland, and worked as a coal miner before establishing a furniture business. After encountering financial troubles, he robbed a bank and was sentenced to jail. He fled from prison after a Russian-backed separatist rebellion in the Donbas in 2014, weeks after<a href="https://www.thenationalnews.com/opinion/comment/russia-s-crimean-landgrab-has-changed-the-face-of-international-relations-1.836102" target="_blank"> Moscow’s annexation of Ukraine’s Crimean Peninsula</a>. Mr Tatarsky joined separatist rebels and fought on the front line before turning to blogging. Last September, he told the media at a ceremony in the Kremlin: "We will defeat everyone. We will kill everyone. We will rob everyone as necessary. Just as we like it."