The discovery of video footage earlier this month showing Russian-speaking militants among those fighting with the Islamic State (IS) group at Kobani prompted the questions: who are these fighters, and to which jamaat (fighting unit) do they belong?
Pro-Islamic State accounts on the Russian social-networking site VKontakte mentioned that a faction named Jamaat Abu Kamilya ("Abu Kamil's jamaat") had suffered losses in Kobani, and that the faction contained ethnic Nogais. One account reported that the faction's former military emir (leader) had been an ethnic Nogai named Abu Ali.
The Nogais are a Turkic people who adopted Sunni Islam in the 14th century. They are not ethnically or linguistically related to the Chechens. Most live in Daghestan, but there are also Nogai communities in Chechnya, Karachayevo-Cherkessia, Kabardino-Balkaria, and Stavropol Krai.
While it is impossible to verify the reports that the Russian-speaking fighters in the Islamic State group's forces around Kobani include Nogais, if the reports are accurate this would be the first report of Nogai participation in Islamic State.
There is evidence that a wide variety of North Caucasian ethnic groups are fighting in Syria, including for Islamic State. Many of these militants are displaced from the conflict in Russia's North Caucasus region.
Russian media reports have claimed that a Nogai jamaat fought alongside Arab foreign fighters in Chechnya in 1999, and that Nogais have since been involved in unrest in the North Caucasus, via the Nogai Jamaat, a little-known Islamist group linked to the Caucasus Emirate.
A member of the Nogai Jamaat was allegedly behind the deadly 2011 suicide attack at Moscow's Domodedovo Airport.
Islamic State militants also include ethnic Karachais (such as Abu Jihad, Umar Shishani's second-in-command), Chechens and Daghestanis. Some of these militants were previously active in the anti-Russian insurgency.
On October 14, Russian media sources reported that a 31-year-old resident of Kabardino-Balkaria is under suspicion of fighting in Syria, possibly for Islamic State although it is not clear with which group, since the Russian authorities have refused to name the factions in which Russian nationals are suspected of participating. The man entered Syria via Egypt, according to reports, and his mother later discovered he had gone to take part in the armed conflict.
-- Joanna Paraszczuk