Russian special force have stormed a detention centre in the south of the country, killing inmates accused of links to Islamist terror cells who had previously taken two staff members hostage, according to state-funded news channel RT.

Reporters on the scene reported the sounds of gunfire, while multiple ambulances were seen arriving at the prison in footage on social media.

The hostages at the pretrial detention centre in Rostov-on-Don were uninjured, Russia’s Federal Penitentiary Service said in an official statement.

It said that the hostage takers had been “liquidated,” without offering further comment.

A number of local media outlets reported that at least some of the prisoners had been killed.

Earlier, state news agency Tass, citing unnamed sources in law enforcement, had said that six hostage takers were in the central courtyard of the Rostov region’s Detention Centre No. 1, armed with a penknife, a rubber baton and a fire axe.

The prisoners include men accused of links to the Islamic State group, Tass claimed.

Images posted on social media appeared to show at least two of the hostage-takers wearing a headband that resembled the Islamic State’s flag.

Other images showed prisoners wielding knives.

RT claimed three of the hostage-takers had already been sentenced on terrorism charges, including disseminating extremist information and plotting to blow up a Russian courthouse.

IS have carried out a number of attacks on Russian soil in recent years.

An affiliate of IS claimed responsibility for the most recent attack in March, when gunmen opened fire on a crowd at a concert hall in suburban Moscow, killing 145 people.