Fatal Blasts in Volgograd, Russia

A woman puts a flower outside wreckage of a trolleybus, Volgograd, Russia, Dec. 31, 2013. 

Flowers and toys are placed at the site of a trolleybus bombing in Volgograd, Russia, Dec. 31, 2013.

A woman cries outside the main railway station, Volgograd, Russia, Dec. 31, 2013. 

Russian soldiers patrol the Battle of Stalingrad memorial in Volgograd, Russia, Dec. 31, 2013. 

Russian police officers check the identity papers of migrant workers arriving at Red Square ahead of the New Year's Eve festivities, Moscow, Russia, Dec. 31, 2013. 

Investigators work at the site of a blast on a bus in Volgograd, Russia, Dec. 30, 2013.

Members of the emergency services work at the site of a bomb blast on a bus in Volgograd, Russia, Dec. 30, 2013.

The flash of an explosion illuminates the entrance to the railway station, Volgograd, Russia, Dec. 29, 2013. 

Smoke pours out of the railway station after an explosion, Volgograd, Russia, Dec. 29, 2013. 

Investigators work at the site of an explosion near the entrance to a train station in Volgograd, Russia, Dec. 29, 2013. 

Medics help wounded people near the entrance to a railway station in Volgograd, Russia, Dec. 29, 2013. 

This image made available by the Volgograd Mayor's Office shows bodies at an entrance to the railway station after a suicide attack in Volgograd, Dec. 29, 2013.

Interior Ministry guards are seen near a train station after a suicide attack, Volgograd, Russia, Dec. 29, 2013.