Russian officials say a suspected female suicide bomber detonated an explosive device on a passenger bus in the southern city of Volgograd, killing at least six people and injuring at least 33 others, some seriously.
A spokesman for the Russian National Antiterrorist Committee said the explosion occurred at 2:05 p.m. local time. He said the country's rapid response unit was coordinating the activity of security authorities and police in order to prevent possible further explosions.
A Russian news organization showed dash cam footage
of the explosion as it occurred.
A spokesman for Russia's Investigative Committee, Vladimir Markin, said the suicide bomber had been identified as a 30-year-old native of Daghestan by the name of Naida Asiyalova.
Markin said according to available information, the woman boarded the bus and the explosion took place almost immediately. He said this has been confirmed by a woman who survived the blast.
Russian state television showed pictures of Asiyalova's passport. Security officials said she had been the wife of a North Caucasus insurgent leader and a convert to Islam.
Markin said officials have opened a formal probe into terrorism, murder, and the illegal use of firearms.
Video footage of the explosion shown on state television showed a massive blast rocking the bus as it traveled on the six-lane road.
Officials say there were some 40 people on the bus when the explosion happened.
No one has claimed responsibility.
Volgograd is located several hundred kilometers to the north of Russia's North Caucasus region where Russian forces have been battling Islamic militants for years.
With reporting from Interfax, ITAR-TASS, Rossiya 24 TV, and Reuters