One of the detainees, Russian citizen, three others come from Central Asian countries. According to the FSB, in the preparation of the attacks involved two suicide bombers, a specialist in the production of explosive devices and the emissary of the terrorist organization "Islamic state". The names of the detainees FSB calls.

In the Moscow region, according to the FSB, was liquidated laboratory on manufacture of improvised explosive devices.

In late July, the FSB announced the arrest of seven people from Central Asia, who were preparing terrorist attacks in St. Petersburg. The names of the suspects were not named.

3 April 2017 in St. Petersburg, an explosion occurred in a subway car. The victims were 15 people. During the investigation, was arrested 10 people. The organizers of the terrorist attack, the investigation believes the brothers was and Akram Asimovich. They claim that after the arrest had been tortured.