A bomb blast ripped through a passenger bus in the southern Russian city of Volgograd on Monday, killing at least six people and injuring at least 27 others, officials said.
The blast was caused by “an unspecified explosive device,” the National Anti-Terrorism Committee said in a statement. According to the Interfax news agency, which cited Russian investigators, a female suicide bomber was responsible for the blast.
The anti-terrorism agency, which is part of the Federal Security Service, said investigators were on the scene.
A total of 40 people were on the city bus at the time of the explosion, said Irina Gogolyeva, a spokeswoman for the Emergency Situations Ministry.
Many of the injured were hospitalized in serious condition, the state news agency ITAR-Tass reported.