Details added, first version posted at 14:16
At least 13 people were killed Sunday by a female suicide bomber who blew herself up at the main railway station in the southern Russian city of Volgograd, dpa reported.
The blast raised fears about terrorism attacks some six weeks before the opening of the Winter Olympic Games in the Black Sea resort of Sochi, some 700 kilometres south of Volgograd.
Vladimir Markin, a prosecutions spokesman, said initial inquiries indicated a woman blew herself up in the station in a terrorist attack, the Interfax news agency reported. About 50 people were injured by the blast.
In October, a suicide bomber blew herself up in a Volgograd bus, killing six passengers.
Witnesses said the station was significantly damaged by the blast. Ambulances and firefighters were sent to the scene.
Doku Umarov, the leader of Islamist rebels in Chechnya, has called for terrorist attacks to disrupt the Games. The Kremlin has vowed to hold the Games without danger.