Security authorities in the Siberian cities of Kemerovo and Novosibirsk say they have apprehended an unspecified number of alleged supporters of the banned Hizb ut-Tahrir Islamic group.
Human rights groups have criticized the government's "abuse" of counterterrorism laws and the use of "secret witnesses" and other methods in prosecuting critics and religious groups to silence dissent.
The Federal Security Service (FSB) said on April 21 that alleged members of the group that was banned in the country in 2003 "carried out anti-constitutional activities based on the doctrine of the creation of a world caliphate."
Hizb ut-Tahrir, which is also banned in Central Asia, says its movement is peaceful.
The FSB did not say how many suspects have been apprehended.
Hizb ut-Tahrir is a global organization based in London that seeks to unite all Muslim countries into an Islamic caliphate, but it says its methods for reaching that goal are peaceful.
Russia's detention of some younger alleged members of the group has sparked protests by parents who say their children have been arrested on political grounds.