Russian news agencies said security agents have detained 15 members of the Jehovah's Witnesses in the North Caucasus region of Daghestan, in the latest roundup targeting members of the religious group.
Interfax and Tass reported on June 6 that the 15 were detained and charged with organizing "conspiratorial gatherings with the aim of studying extremist literature."
Interfax quoted an unnamed law enforcement official as saying that agents seized a large amount of "propaganda material" that was "used by suspects to spread extremist ideology and engage locals, including children, into unlawful activities."
It wasn't immediately clear when the detentions occurred.
A spokesman for the religious group said four members -- three men and one woman -- had been detained in Daghestan on June 1, in raids in four towns in Daghestan, but he could not confirm the larger number.
The Jehovah's Witnesses have been under intense pressure in Russia since the Supreme Court ruled in 2017 that it was an extremist organization. The group has reported a growing number of raids, detentions and torture of its adherents across Russia in recent months.
The organization said that as of June 3, there were 35 members in pretrial detention, and 207 total facing criminal charges across the country.
Headquartered in the United States, the Jehovah's Witnesses have been viewed with suspicion in Russia for decades, for its members' views about military service, voting, and government authority in general.
The group says it has about 170,000 adherents in Russia.