Siarhei Mazol was sentenced by Brest Regional Court under Part 1 of Article 361-4 of the Criminal Code. The case was considered by Judge Katsiaryna Hruda from June 21 to June 23, 2023.

Siarhei was arrested on March 9, 2023. First, he was tried twice under Part 2 of Article 19.11 of the Code of Administrative Offenses. He was sentenced to five and fifteen days of imprisonment. And on March 29, 2023, the man was detained in a criminal case.

The basis for the criminal case was the fact that on March 11, 2022 Mazol sent a message to the telegram bot "NEXTA Editorial Office": "Stolin, Brest region. Border with Ukraine. I confirm that missiles have been fired from a fighter jet". In this way, Mazol deliberately promoted the activities of the "NEXTA" extremist group, according to the prosecution's version.

But at the trial, Mazol said that he had learned about the status of the "extremist group" of the NEXTA telegram channel "only 4 months ago" (that is, in February 2023). When he learned about the status, he unsubscribed (and also unsubscribed from BYPOL, Belaruski Hayun, Realnaya Belarus).
It is known that Siarhei was sentenced to imprisonment. The place of detention is unknown. On September 5, 2023, the court held an appeal hearing. The sentence became effective.

      On September 8, 2023, Siarhei Mazol was added to the list of Belarusian citizens, foreign citizens and stateless persons involved in extremist activities.

He was pardoned and released on September 16, 2024.