The ministry said members of Takfir wal-Hijra - a group formed in Egypt in the 1960s and outlawed in Russia in 2010 - had been discovered hiding weapons and explosives in their apartments but provided few other details.
It said the group had been funding its activities by "conducting general crime".
Takfir wal-Hijra was quashed in Egypt in the 1970s but is believed to have cells linked to Al-Qaeda in several European and other countries.
A top guerrilla commander in the North Caucasus who has claimed responsibility for a string of deadly suicide bombings in Moscow has threatened to target the Sochi Games.