Security officers near the Federal Security Service (FSB) headquarters in Moscow. (Reuters)

The Russian Federal Security Service (FSB) revealed on Thursday that the special services of Ukraine and their agents, including from among the Russian opposition, were behind the terrorist attack on a cafe in the center of St. Petersburg, which killed Russian military reporter Vladlen Tatarsky.

Journalist Vladlen Tatarsky was brutally assassinated on April 2 in a cafe in St. Petersburg, Russia. A day after, The Russian Investigative Committee detained Daria Trepova in St. Petersburg, on account of her involvement in the killing of Tatarsky. At the time, the Russian National Anti-Terrorism Committee revealed that the Ukrainian Special Services and the supporters of the extremist Anti-Corruption Foundation (FBK) planned the terrorist attack.

"After the start of the special military operation, the leaders of the FBK Leonid Volkov and Ivan Zhdanov have repeatedly stated the need to conduct subversive activities in Russia in order to change the constitutional order 'by any available means' ... As a result, on April 2, Daria Trepova committed the terrorist attack," the FSB said in a statement.

As confirmed by the Russian Investigative Committee, the death of the war reporter was the result of the detonation of an explosive device. In a related development, the FSB detailed that Yuriy Denisov, a Ukrainian national who is a member of the Ukrainian sabotage group, orchestrated the murder and supplied Trepova with an explosive device.

"On the instructions of the Ukrainian special services, Denisov arrived from Kiev through the territory of Latvia to the capital [Moscow] region in February 2023, where he collected information about the lifestyle and places visited by ... [Tatarsky] ... After the terrorist attack, Denisov flew from Russia in transit through Armenia to Turkey on April 3. The procedure for putting him on the international wanted list has been initiated," the FSB said.

Tatarsky's death comes after the assassination of Alexander Dugin’s daughter Darya Dugina in August 2022, allegedly also by the Ukrainian special services.

The spokesperson of the Russian Foreign Ministry, Maria Zakharova, pointed out that pro-Russian journalists and thinkers are constantly threatened by Ukraine in an attempt to silence them.

US intelligence agencies believe that bodies pertaining to the Ukrainian government have authorized the car bomb attack which killed political philosopher Alexander Dugin's daughter, Darya Dugina. The US officials providing the information in question divulged it to The New York Times.

US officials fear that this part of Washington's covert campaign could widen the scope and severity of the conflict.

The officials claimed that the US did not provide intelligence or other forms of assistance. The NYT sources also claimed that they were not aware of the operation beforehand, and had they been consulted, they would have opposed the assassination.