MOSCOW — A deadly suicide bombing at a crowded railroad station in southern Russia on Sunday, followed by a blast in a trolley bus on Monday in the same city, raised the specter of a new wave of terrorism just six weeks before the Winter Olympics in Sochi.
President Vladimir V. Putin’s government has worked to protect the Olympics with some of the most extensive security measures ever imposed for the Games. But the bombings, in Volgograd, underscored the threat the country faces from a radical Islamic insurgency in the North Caucasus that has periodically spilled into the Russian heartland, with deadly results, including several recent attacks.
Security has become a paramount concern at all major international sporting events, especially in the wake of the bombing at the Boston Marathon in April, but never before has an Olympic host country experienced terrorist violence on this scale soon before the Games. And would-be attackers may have more targets in mind than the Russian state.
Current and former American law enforcement and intelligence officials said Sunday that they were more concerned about security in Russia during the Sochi Games than they have been about any other Olympics since Athens in 2004.
Russian officials attributed the explosion on Sunday to a bomb packed with shrapnel, possibly carried in a bag or backpack. It was detonated in the main railroad station in Volgograd, a city 550 miles south of Moscow and 400 miles northeast of Sochi. The bomb blew out windows in the building’s facade and left a horrific scene of carnage at its main entrance. At least 16 people were killed, and nearly three dozen others were wounded, some of them critically, meaning the death toll could still rise.
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