Russian authorities have said that a bomb blast was the likely reason for a train derailment on the railway line between Moscow and Saint Petersburg yesterday in which 60 people were injured.
It has been reported that 12 carriages were derailed in the incident about 200km south-east of Saint Petersburg.
Some 60 people needed medical attention and two of the injured are in a critical condition.
Prosecutors have opened a criminal investigation into suspected terrorism.
A hole apparently caused by a blast has been found under the rails.
The Moscow-Saint Petersburg train is popular with foreign tourists.
Russia has seen a lull in insurgent attacks in its main population centres since a spate of suicide bombings in Moscow in 2003 and 2004 that were blamed on Chechen rebels.
