The leader of a Caucasus Islamist group in Russia's restive Dagestan region has been killed in a mountain raid that included air strikes, Russian security services and Islamists said Tuesday.

Four people died in the operation by Russia's special forces and military, Dagestan's interior ministry said.

The current leader of the Caucasus Emirate group, Magomed Suleimanov, was among those killed, the National Anti-terrorist Committee (NAK) said in a statement to Russian news agencies.

Insurgent website Kavkaz Center also said that Suleimanov, 39, was killed in the course of a two-day raid near the mountain village of Gimry which included strikes from helicopters.

The Caucasus Emirate group had claimed several major attacks on Russian soil in recent years, including the Domodedovo airport bombing, which killed 27 people, and more recently twin blasts in the southern city of Volgograd which killed 34.

Suleimanov's biography on insurgent websites says he was educated in the Al-Fatih Islamic Institute in Damascus after which he began recruiting fighters in his home village Gimry.

He orchestrated several attacks in the region, including a suicide blast that killed respected Muslim cleric Said Afandi in his home along with seven others in 2012.

He has only been the head of the Caucasus Emirate group since July, after a hiatus of more than a year since its longtime leader Doku Umarov was killed in March 2014.

Besides lack of leadership, the Caucasus Emirate group, which was formed in 2007, has been weakened by an exodus of fighters joining the Islamic State group in Syria and switching allegiance to IS leader Abu Bakr al-Baghdadi.

In June, militants in four Caucasus regions pledged allegiance to the IS, which established its own governor for the Caucasus, Rustam Aselderov.