Russia on Sunday announced that in a special operation carried out by its anti-terrorism forces, at least 10 terrorists affiliated with the Islamic State (Isis) were gunned down in Nalchik in an early-morning raid, reports said.

Russian state news agency Interfax said that in the operation, which was still under way, at least 10 Isis militants were killed in Nalchik â€” the capital city of the Kabardino-Balkar Republic in Southern Russia.

"During the active phase of a special operation near Nalchik, according to preliminary information, 10 militants were neutralised," Interfax quoted Russia's National Anti-Terrorism Committee (NAC) as saying.

"They were all members of armed groups that had sworn allegiance to the international terrorist organisation Isis," the report added.

According to Russian news agency RIA Novosti, those killed were part of the "core" group of the "underground" grourp in Kabardino-Balkar, which has sworn allegiance to Isis.

The report noted that the operation was headed by FSB, which is Vladimir Putin's immensely powerful modern-day KGB. The operation began at 8 am, it is reported.

In the FSB operations last week, a local Isis leader was shot dead by the security forces in Nalchik during a raid.

Isis leader Robert Zankishiev â€” a 27-year-old part of an Isis affiliate group known as "Vilayat KBK" â€” was killed after special forces stormed a high-rise building in the southern part of the city, The Moscow Times had reported.