These were the separatist groups signing the press release (written in Russian) from yesterday's conference in Istanbul:
* World Chechen Congress
* Caucasian Union
* Karelian National Movement
* Chuvash-Volga-Bulgarian Diplomatic Council
* Government of Tatarstan in exile
* Council of United Circassia
* Cossack national liberation movement "Ѣзиковъй Ѣртаул "
* Kuban Conservative Movement "Січова Братія""
* Supreme Council of the Nogai People
* Dagestan National Center
* Free Bjarmia/Pomorie
* Pomorska Sloboda
* International organization "Free Circassia"
* Public organization "Strong Azerbaijan"
* Circassian congress
* Round table - Free Caucasus
It should be noted that some (but not all) of these groups are far-right or openly racist.