Moscow (CNN) -- Russia's security service has foiled a plot to attack the 2014 Winter Olympics in the Black Sea city of Sochi, state media reported Thursday.
Authorities arrested three men this week in Georgia's breakaway republic of Abkhazia on charges of plotting the attack in a joint operation with Abkhazian security services, the Russian National Anti-Terrorism Committee said, according to the state-run RIA Novosti news agency.
The three are suspected of being ringleaders of a regional cell of the North Caucasus-based terrorist group Caucasus Emirate.
Police seized weapons, including three portable surface-to-air missiles, two anti-tank guided missiles, a mortar and a flamethrower, the news agency said.
The militants planned to move the arms to the nearby resort city of Sochi and use them to carry out terrorist attacks during the Games, it quoted the National Anti-Terrorism Committee as saying.
The U.S. State Department added the Caucasus Emirate, a Chechen group based in the North Caucasus, to its list of foreign terrorist groups, and has authorized a reward of up to $5 million for information leading to the location of its leader, Doku Umarov.
The State Department said Umarov organized a suicide bombing outside the Chechen Interior Ministry in May 2009.
His group also claimed responsibility for last year's bombing of Domodedovo Airport in Moscow that killed 36 people, the 2010 bombings of the Moscow subway that killed 40 and the 2009 bombing of the high-speed Nevsky Express train in which 28 people died.
CNN's Alla Eshchenko contributed to this report.