MOSCOW — Russian prosecutors launched a terrorism investigation Tuesday of a bomb explosion that derailed an express train, overturning carriages and injuring 60 people.
An improvised device was placed under the rails just before a bridge in an effort to make the prestigious Nevsky Express crash into a narrow ravine, which could have caused many more casualties, authorities said. The high-speed train between Moscow and St. Petersburg, frequently used by businesspeople, foreign tourists, politicians and government officials, was traveling about 120 mph when it derailed Monday evening.
Television video showed a 6-foot-wide crater in the gravel rail bed, a broken rail and several cars lying on their sides. The bomb was equivalent to about 6 pounds of TNT, investigators said.
Twenty-five of those hurt were hospitalized, five with grave injuries, authorities said. All of those hospitalized were reported to be Russian citizens.
At the moment of the blast, which hit the front of the train, "our electric locomotive jumped up immediately and glass started flying," Alexei Fedotov, the engine driver, said on state-run television.
"Of course, we were deafened. But we applied emergency braking and cut off electric power to the engine. Then our cabin roof simply flew away."
The blast occurred near the town of Malaya Vishera, about 300 miles northwest of Moscow. Law enforcement authorities said investigators had found wires that might have been used to trigger the explosion.
"The electrical wires, the so-called noodles, were discovered not far from the site of the explosion, in a ravine where the man who connected them must have been," an investigator told the Interfax news agency.
Residents had seen suspicious men in the area in the last few days, authorities added. Composite drawings of two suspects had been prepared by Tuesday evening, Russian media reported.
Politicians and analysts suggested that the attack could be linked to separatist rebels in Chechnya or other Islamic militants in southern Russia's troubled Caucasus region. Some Kremlin critics expressed concern that it could be a provocation aimed at influencing Russian politics, perhaps to offer President Vladimir V. Putin a pretext to remain in power.
A suicide bombing on a commuter train in southern Russia killed 44 people Dec. 5, 2003, two days before Russian parliamentary elections. Two months later, a device exploded on a subway car in Moscow, killing 41 people. Both incidents were blamed on Chechen separatists.
