A bomb explosion killed eight and injured over 50 people, traveling in a passenger bus Wednesday in a central Russian city.
Investigators were trying to determine whether the explosive device was carried by a passenger or had been planted somewhere inside or beneath the bus in Togliatti, according to Russian news agencies.
The Volga River city is headquarters to Russia's largest carmaker, AvtoVAZ and has a reputation for gang violence as varying groups have competed for control over the lucrative state-owned factory. A factory spokesman could not say whether there were factory workers among the victims.
With nearly a month remaining before parliamentary elections, the blast raised fears of similar violence that has occurred before other elections in the past.
"Due to (the blast's) character, its consequences, the main version being considered is a terrorist attack," said Yuri Rozhin, director of the regional division of the Federal Security Service.
Images on Russian television showed a long green bus, its windows blown out and its roof partially detached from the force of the explosion. Paramedics attended to people with bloody faces and legs.
Valery Matkovsky, a local emergency official, said that eight people had died and 53 suffered burns and shrapnel wounds. Russian media said that one child was among the dead.
The explosion, which shattered windows on nearby residential buildings, occurred near a bus stop in the city center as people were going to work. A group of college students had left the bus at the stop just seconds before the blast, and about 20 students were among the injured, NTV reported.
Vadim Blagodarny, a 20-year-old photographer, said people walked around stunned and in shock in the minutes after the blast, as investigators picked through the carnage.
"If it had gone off just a minute earlier, it would have been much, much worse," he said.
Security at the scene was heavy, and some photographers were either detained or had their equipment confiscated.
Some Russian politicians immediately speculated that the blast was an attempt to sow social unrest. Earlier this fall, the head of the country's main security agency warned of the potential for pre-election violence and said police agencies would bolster security and surveillance nationwide before the Dec. 2 vote.
In 1999, just three months before national elections, there were explosions in several residential buildings in Moscow and other Russian towns, killing hundreds. Opposition activists and Kremlin critics said the government used the blasts to justify sending federal troops back into violence-wracked Chechnya, launching the second war in a decade in the region.