The suicide bombers who committed terrorist attacks in Volgograd in late December came from the North Caucasus, a source from the law enforcement authorities told Interfax quoting tentative data.

"A preliminary opinion about circumstances of the terror attacks has been made. A tentative analysis based on evidence indicates that the suicide bombers who blew themselves up at the Volgograd railroad station and on the route 15 trolley bus were not trained in the Volgograd region but were ordered to come here and destabilize the city with suicide bombings taking a heavy death and injury toll," he said.

Judging by preliminary information, the suicide bombers were trained in a North Caucasian region where federal forces are actively suppressing militants, the source added.

In his words, suicide bombers might have stealthily come to the Volgograd region along dirt roads, bypassing motorways controlled by the police.

Remains found on the bombing site show that the trolley bus terror act was perpetrated by a man, the source said.

The law enforcement authorities are investigating the terror attacks perpetrated in Volgograd on December 29 and 30, the National Antiterrorism Committee said earlier in the day.

The explosions at the Volgograd railroad station on December 29 and on a trolley bus on December 30 killed 34 people and injured dozens.

The Russian Health Ministry press service said on Thursday 62 attack victims were hospitalized in Volgograd and Moscow, and five of them were in critical condition.

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