Three men were arrested this week on suspicion of plotting the attack , state media reports . Police seized weapons , including anti - tank missiles , state media reports . The Russian resort city of Kazan will host the Winter Olympics in 2014 .
Three men were arrested this week on suspicion of plotting the attack , state media says . Police seize weapons , including anti-tank missiles , state media reports . The Russian resort city of Sochi will host the Winter Olympics in 2014 .