A second, less powerful bomb exploded today at the site of a Russian train crash, though no one was injured, the head of Russia's state railway operator said.
Russian Railways chief Vladimir Yakunin said the bomb went off at 2:00 p.m. (1100 GMT) near the site of the first blast which officials said caused the luxury express train to career off the tracks.
The first bomb caused the derailment of a luxury express train that killed dozens and injured nearly 100, Russia's security agency said on Saturday, in the worst attack on the country's heartland in five years.
The 14-carriage Nevsky Express, carrying 682 passengers and 29 crew, was derailed last night on the busy main line between Moscow and Russia's second city, St Petersburg.
"Criminal experts say that based on preliminary findings a bomb equivalent to 7kg of TNT was detonated," the head of the Federal Security Service (FSB) domestic intelligence agency, Alexander Bortnikov, told Russian President Dmitry Medvedev.
Detectives said they had found fragments of what they believed was a bomb and opened a criminal case on charges of terrorism. No one has so far publicly claimed responsibility for the incident.
The attack, Russia's worst outside the turbulent North Caucasus since a series of 2004 suicide bombings in Moscow, has stoked fears of a surge in attacks in Russia's historic heartland by Islamist rebels from Russia's southern flank.
The force of the blast jolted at least two carriages off the rails at 9:34 p.m. (1834 GMT) yesterday near the village of Uglovka about 350 km north of Moscow.
Hundreds of rescue workers toiled through the night to search for survivors, cutting through the tangled steel of at least two wrecked train carriages which lay battered beside the rails.
A Reuters photographer saw soldiers carrying four body bags away from the scene.
Russia's Emergency Ministry said at least 26 people had been confirmed dead with another 18 missing, though one rescue official earlier put the death toll as high as 39. The ministry said 96 people had been injured.
ATTACK
Medvedev, speaking to senior officials at an emergency meeting, sent his condolences to the families of the dead and told ministers to ensure everyone received proper medical care and compensation.
Some witnesses said they heard a loud bang, but another passenger told reporters in St Petersburg there had been no blast.
Russian Railways chief Vladimir Yakunin told reporters at the scene that he believed the blast showed many similarities to an explosion in August 2007 which derailed a similar Nevsky Express train on the same route, injuring 30 people.
Prosecutors at the time arrested two residents of the mainly Muslim North Caucasus region of Ingushetia, but said the mastermind behind the attack was ex-soldier Pavel Kosolapov, a former associate of late Chechen rebel commander Shamil Basayev.
An upsurge in attacks this year along the mainly Muslim republics which make up Russia's southern flank have raised fears that Islamist rebels could mount a new wave of attacks in Russia's historic heartland around Moscow and St Petersburg.
In 2004, a spate of suicide bombings and attacks in Moscow were followed by the Beslan school hostage crisis.
"The so-called Chechen trace is traditionally viewed as the main one during investigations of such disasters," said Alexei Mukhin, an analyst at the Centre for Political Information.
But Mukhin added that outdated Soviet-era infrastructure was often the cause of major accidents in Russia.
Friday's railway disaster was the deadliest since December 2003 when a bomb blast tore through a passenger train in the North Caucasus, killing 47 people.
The derailment has delayed about 27,000 people as transport officials try to divert trains onto smaller lines, railway officials said.