Authorities Round Up Dozens After Bombings in Volgograd

No indication any were involved in the terror acts, for which no one has claimed responsibility

Police detained dozens of people on Tuesday in sweeps through the Russian city of Volgograd after two deadly attacks in less than 24 hours that raised security fears ahead of the Winter Olympics.

A man wounded when a bomber set off a blast in the city's railway station on Sunday died overnight, bringing the toll in that attack to 18. Regional governor Sergei Bazhenov said 16 died in a trolleybus bombing on Monday.