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Deadly blast at Russia's Volgograd station

29 December 2013 Last updated at 18:10 GMT

An explosion at a train station in the southern Russian city of Volgograd has killed at least 15 people, according to reports.

A female suicide bomber was thought to be responsible for the blast, Russia's anti-terrorism committee said.

Moscow is concerned militant groups could be ramping up violence in the run up to the the 2014 winter Olympic Games in Sochi.

Daniel Sandford reports.