Moscow: A blast that tore through an electric bus in the southern Russian city of Volgograd during Monday's morning rush hour, killing 14, was probably carried out by suicide bombers from the same organization behind a railway explosion a day earlier, officials said.
Together more than 30 people were killed in the explosions, putting the city of one million on edge and highlighting the terrorist threat Russia is facing as it prepares to host February's Winter Games in Sochi, President Vladimir Putin's pet project. While terrorists may find it hard to get to the tightly guarded Olympic facilities, the bombings have shown they can hit civilian targets elsewhere in Russia with shocking ease.
Volgograd, located about 650 kilometers (400 miles) northeast of Sochi, serves as a key transport hub for southern Russia, with numerous bus routes linking it to volatile provinces in Russia's North Caucasus, where insurgents have been seeking an Islamic state.
Vladimir Markin, the spokesman for Russia's main investigative agency said Monday's explosion involved a bomb similar to the one used in Sunday's bombing at the city's main railway station. ''That confirms the investigators' version that the two terror attacks were linked,'' Markin said in a statement. ''They could have been prepared in one place.''
Suicide bombings and other terror attacks have rocked Russia for years, but most recently have been confined to the North Caucasus region. The successive attacks in Volgograd signaled that militants may be using the transportation hub as a renewed way of showing their reach outside their restive region.
Monday's explosion ripped away much of the bus's exterior and shattered windows in nearby buildings. It virtually paralysed public transport in the city, forcing many residents to walk long distances to get to work.
Twin bombings on the Moscow subway in March 2010 by female suicide bombers killed 40 people and wounded more than 120. In January 2011, a male suicide bomber struck Moscow's Domodedovo Airport, killing 37 people and injuring more than 180.