Russian authorities say a bomb is the likely cause of a train derailment on the railway line between Moscow and Saint Petersburg in which 60 people were injured.
"According to preliminary information, the accident happened due to a planted handmade explosive device," state-owned Russian Railways said in a statement.
Russian Railways said that 12 carriages had been derailed in the incident late yesterday near Malaya Vishera in Novgorod province, about 200 kilometres south-east of Saint Petersburg.
"Sixty people sought medical aid and 20 were taken to hospitals in the Novgorod region. Two are in critical condition," the statement said.
Prosecutors opened a criminal investigation into suspected terrorism, the Interfax news agency reported.
A local police source told RIA Novosti that "a bomb equivalent to two kilograms of TNT exploded on the rails." However another law enforcement source told Interfax that it was too early to be sure whether the derailment resulted from an attack.