The leader of the self-proclaimed Caucasus Emirate, Magomed Suleimanov, was killed in a special operation in Russia's North Caucasus region of Daghestan on August 11.
Russia's National Antiterrorist Committee said that Suleimanov was among four militants killed by security forces in Daghestan's Untsukul district.
The pro-militant website Kavkazcenter.com confirmed that Suleimanov, also known as Abu Usman Gimrinsky, "became a martyr" in the August 11 operation.
Suleimanov was announced as the leader of the Caucasus Emirate in April after its previous leader, Aliaskhab Kebekov, was killed by Russia's security forces.
Kebekov took over the Caucasus Emirate leadership in March 2014 after it was announced that its founding leader, Doku Umarov, was killed by Russian federal security troops.
The North Caucasus has become Russia's most violence-plagued region in recent years.
After two separatist wars in Chechnya in the mid-1990s and early 2000s, the Islamic militancy spilled over into other North Caucasus republics, such as Kabardino-Balkaria, Daghestan, and Ingushetia, which Umarov proclaimed as subjects of the Caucasus Emirate in 2007.