Prisoners in Russia’s south-western Volgograd region took prison staff hostage on Friday, Russian media reported.

The hostage-taking took place during a meeting of the disciplinary committee, the prison administration said in a statement. The Russian administration added that measures were being taken to free the hostages and confirmed that no one was injured in the incident.

Activists on social media platforms in Russia posted a video showing the detention of the uniformed officers.

According to some unconfirmed reports, several people were killed inside the prison.