Russian authorities raided a remote prison in the southwestern region of Volgograd and “eliminated” four people after inmates rebelled and took several guards hostage.
Special forces were forced to go to the IK-19 Surovikino facility after knife-wielding prisoners claiming to be Islamic State (IS) militants hijacked staff and claimed control of the sprawling complex.
An unconfirmed image posted on social media appeared to show an inmate holding a knife over blood-stained guards.
State news agency TASS said a prison service worker was killed.
Russia’s National Guard said snipers shot dead four prisoners during the rescue operation, while local media reported that all hostages had been rescued.
In footage posted to Telegram by the National Guard, known as Rosgvardia, heavily armed soldiers were filmed arriving at the prison.
Russia’s Federal Prison Service said in a statement that the attack began during a meeting of the disciplinary committee.
It was unclear how many hostages were taken, but some reports in Russian media said the prison director and deputy director had been captured.
In dramatic footage, unconfirmed footage shows a man standing in a prison courtyard apparently brandishing a knife. Another video showed one of the attackers pledging allegiance to the Islamic State.
Volgograd Region Governor Andrei Bocharov said earlier that the hostage-taking incident “posed no threat to civilians.”
President Vladimir Putin was filmed attending a virtual meeting with security chiefs, where he was updated on the situation.
The hostage-taking in Volgograd was the second such incident this summer, after Six prisoners sworn allegiance The Islamic State group captured two guards at a facility in the neighboring Rostov region.
Following the attack, five prisoners were killed and a sixth was sentenced to 20 years in prison.
Prosecutors said they had opened a case related to the hostage-taking.
IK-19 Surovikino was a heavily fortified penal colony. It is believed to house around 1,200 prisoners.