Russia has launched one of the biggest security operations in Olympic history a month before the start of the Winter Games in the Black Sea resort of Sochi, BBC reports.
The authorities are deploying more than 30,000 police and interior ministry troops and limiting access to the area.
The main concern is the threat of attack by Islamist militants from the restive North Caucasus region.
Russia's most wanted man, the Chechen rebel leader Doku Umarov, has urged his fighters to target the Winter Olympics.
The recent deadly bombings in Volgograd have intensified those worries, according to BBC.
The bombings prompted President Vladimir Putin to order further security measures and personally inspect Olympic sites.
"Starting 7 January, all divisions responsible for ensuring the guests' security at the Games are being put on combat alert," Emergency Situations Minister Vladimir Puchkov said.
Last year, Russian authorities announced that protest rallies would be banned in the Games area.
But a recent decree says protests during the Games can be held if agreed with the authorities.
A new Russian law banning "homosexual propaganda" towards people under 18 had led some to call for the Games to be boycotted.
However, President Putin has insisted gay and lesbian athletes will feel at ease.