Sergei was arrested right at college during classes in late December 2023. A pro-government film (April 2024) reported that six teenagers allegedly united into an "anarchist cell called 'Black Nightingales,'" which was created "under the leadership of the National Liberation Army of Ukraine" by 16-year-old Ukrainian citizen Maria Misiuk.
ONT staff claim the teenagers united to carry out acts of sabotage, following a tip, in Belarus and then in Russia. Maria is charged under Part 2 of Article 289 of the Criminal Code (act of terrorism). According to the report, 16-year-old Maria Misyuk moved with her family from Ukraine to Belarus in 2022, where she created an "anarchist cell to prepare terrorist attacks." Among those detained are college students in Baranovichi, Nesvizh, Mir, Minsk, and Luninets. They are Trofim Borisov, Sergey Zhigalyov , Dmitry Zakhoroshko, Anastasia Klimenko, and Alexandra Pulinovich. According to ONT staff, the young people gathered in a Baranovichi apartment to prepare for their first major action—to assemble explosives and blow up the Baranovichi police station or prosecutor's office. The charges against the remaining five participants are unknown, as are their statuses and locations.
After being transferred to the penal colony, Sergei was immediately placed in a punishment cell for a month.
