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.The authorities are deploying more than 30,000 police and interior ministry troops and limiting access to the area, BBC reported.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 BBC's Steven Rosenberg in Moscow says recent deadly bombings in Volgograd have intensified those worries.Security zones"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."Every facility will be put under protection and a space-based monitoring system will be launched."Russian officials are establishing two security zones to protect the games.A "controlled zone" near Olympic venues will limit access to people with tickets and proof of identity while another "forbidden zone" will be in place in large areas around Sochi.Vehicles not registered locally and which do not have special accreditation will be banned from the city. The sale of firearms, explosives and ammunition will also be prohibited.Security fears have been heightened after two suicide bomb attacks killed 34 people in the southern city of Volgograd on 29 and 30 December.Investigators believe the perpetrators were two men who arrived in the city from the North Caucasus region.The bombings prompted President Vladimir Putin to order further security measures and personally inspect Olympic sites.In recent years a conflict between Russian forces and separatists in Chechnya has fuelled attacks by Islamists.The violence has spread across the North Caucasus, including to mainly Muslim Ingushetia and Dagestan, killing hundreds of people, among them members of the government and security services.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.ANN.Az