Five members of a banned group were arrested and a homemade bomb packed with shrapnel was defused in the southern town of Nalchik in southern Russia on Saturday.
Nalchik is in the Caucasus region, about 300km from the Winter Olympics which start in Sochi on 7 February.
"Security forces have detained five members of a banned international terrorist organisation," the National Anti-terrorism Committee said in a statement received by Russian news agencies.
Ammunition and grenades were also found, the statement said.
Russian forces went on combat alert last week in Sochi and about 37,000 personnel are now in place to provide security at the Games.
At least 34 people were killed on 29 and 30 December by suicide bombers in Volgograd, which is about 700km northeast of Sochi.
Three people died in a car bomb in Pyatigorsk, another southern city 270km from Sochi, on 27 December.