MOSCOW -Russian special forces stormed a detention centre in the southern city of Rostov on Sunday, killing several hostage takers and freeing the two guards who had been held at knife-point by prisoners with links to Islamic State, Russian media reported.

Intense automatic gunfire could be heard in footage published on Russian telegram channels.

"The criminals were eliminated," Russia's Federal Penitentiary Service said in a statement quoted by the Interfax news agency.

"The employees who were being held hostage were released. They are uninjured," the prison service said.

  - Reuters