Putin-ordered roundup puts 300 Muslims in custody in Moscow MOSCOW, June 9 (UPI) -- About 300 Muslims were taken into custody in Moscow under a government crackdown on Islamic radicals ahead of the 2014 Winter Olympics, security officials say. The Federal Security Service said the Muslims, including 170 foreigners, were arrested Friday at a prayer room in Moscow, the International Business Times reported. President Vladimir Putin ordered the concerted effort to clamp down on Islamic extremists. "We must fight back hard against extremists who, under the banners of radicalism, nationalism and separatism, are trying to split our society," Putin told security officials at the Kremlin Friday. The policy in the fight against corruption, crime and the insurgency has to be carried out harshly and consistently. The situation in the North Caucasus should be kept under particular control. The business news website said the grounds for the arrests, the third roundup in Moscow and St. Petersburg this year, were not disclosed.