MOSCOW: Six detainees, some with links to Islamic State, took guards hostage at a pre-trial detention centre in Russia's southern region of Rostov and demanded free passage in negotiations with the authorities, Russian media reported on Sunday.

The men, who include some already convicted of terrorism offences, knocked out the bars of a window in their cell and entered a guard room where they took at least two prison officers hostage, the Baza Telegram channel said.

State media said that some of the prisoners were accused of terrorism offences including affiliation with the Islamic State militant group, which claimed responsibility for a deadly attack on a Moscow concert hall in March.

Russia's Federal Penitentiary Service said two employees of a pre-trial detention centre in Rostov were taken hostage.

"The institution operates as usual, the situation is under control," the service said on the Telegram messaging app.

It added that law enforcement agencies were on site.

Pictures from the scene showed roads being closed off around the detention centre.

The Interfax news agency said the prisoners had demanded a car and free passage.

  - Reuters