At least eight people were killed and 43 were injured today in an explosion on a bus in the Russian city of Togliatti and authorities said they were treating the suspected bombing as a terrorist act.
The early morning explosion on the bus, which came as people travelled to work in the rush hour, was probably caused by up to 2 kg (4.4 lbs) of explosives, local police sources were quoted by local news agencies as saying, larger than initially stated.
"We have reached the conclusion that this was an act of terrorism," the Samara region governor Vladimir Artyakov said in comments broadcast by Russia's Vesti-24 news channel.
"We are clarifying what type of explosive device was used and we are also clarifying the possibility that there could be more victims."
The officials gave no indication of who might be behind the blast. The Russian prosecutors tend to use the term "terrorism" broadly to describe almost any deliberate attack which incurred big casualties.
In one picture taken by an emergency worker at the scene, the body of one woman could be seen still sitting upright inside the bus.
Other pictures showed the bloody remains of victims, with clothes ripped from bodies -- face down in the debris -- and limbs hanging through blown out windows of the devastated bus.
"Eight people are dead, fifty are injured, with ten rescue groups involved. The first arrived within five minutes of the explosion and more soon after," said Vladimir Markhin, the Togliatti representative of the Russian investigation committee.
