Moscow- The Russian Federal Security Service (FSB) has uncovered a ‘sleeper cell’ linked to ISIS that was active both in Moscow and the North Caucasus region, the Russian National Anti-terrorist Committee said. Four members of the cell were detained.

In Makhachkala, the capital of Russia’s southern Republic of Dagestan, security forces also discovered two extremist hideouts, where they found three ready-to-use improvised explosive devices.

According to investigators, the members of the cell were plotting several potentially high-profile attacks in southern Russian regions, including explosions at public events as well as assaults on officials and the military.

“On October 13 and 14, four members of the so-called sleeping cell of ISIS organization (terrorist organization banned in the Russian Federation) were detained by the FSB and the Ministry of Internal Affairs in Moscow and Makhachkala, all of them are from Dagestan,” the statement issued by Russian National Anti-terrorist Committee said.

The statement added that the detainees are confessing and providing detailed information about their contacts with elements of the organization’s envoys, as well as the preparation of terrorist attacks using IEDs and knives in areas in Dagestan, where large crowds of people gather during large celebrations and social events.

Russian Security forces released video footage showing arrest operations and confessions of the detainees.

One of the videos showed security forces while they were arresting two terrorists in a car and confiscating cold weapons they had with them.

In another video, one of the detainees was shown confessing and admitting that he was planning to travel to one of Central Asia’s republics to buy weapons needed to carry out terrorist attacks and target security forces and headquarters in Dagestan.

Another detainee said that the IEDs they have made were stuffed with iron rollers, which terrorists usually do to maximize the number of injuries.

He explained that they were filled with a magnet to stick to the walls or metal screens, and he confirmed that the cell members had carried out the necessary tests before assembling the IEDs.

Notably, this is the second operation of its kind the Russian security forces have carried out within two weeks and ended up with thwarting the activity of terrorist sleeper cells in Moscow.

Russia’s FSB security service said on October 2 that it had detained members of what it said was ISIS sleeper cell in the Moscow region that had been planning to launch a series of high-profile attacks on the country’s transport system.

The FSB said in a statement on its website that the detentions had occurred on Sept. 30 and that the cell included Russian citizens from the North Caucasus region, who, it said, were committed to trying to set up a global Islamic caliphate and were directed by foreign militants.

It said the cell had been planning to set off explosives in crowded public places and target transport infrastructure.

The FSB said then that it had detained all of the cell’s members, but did not say how many people it had taken into custody. The question of opening criminal cases against them was being decided, it added.