Russian prosecutors have launched a terrorism investigation after a bomb derailed a train travelling from Moscow to St Petersburg, injuring 60 people.

Security chiefs pointed the finger at rebels from the Caucasus but in the tense political atmosphere ahead of forthcoming elections, other scenarios remain possible.

The bomb was placed on the track before a bridge in the Novgorod region, 300 miles north of Moscow. The Nevsky Express, travelling yesterday evening at 80mph, travelled over the bridge before its locomotive and 12 carriages derailed. Investigators said that there would have been more casualties if the train, carrying 251 passengers and 20 staff, had been going more slowly and had tipped over the 100ft bridge into the river below.

Sergei Bednichenko, chief prosecutor for Russia’s North West district, said that the derailment was caused by a homemade explosive device, and a criminal case had been opened under terror laws.

One passenger, Viktoria Kobos, said that there was terrible crash, the windows shattered and the train stopped. “We were in the last wagon, so we were not affected. But in the others, we saw blood and smoke. The restaurant car was literally crushed.”

Russian railways said that 60 people were hurt. Twenty-five were taken to hospital in Novgorod, two in a critical condition. Eight others were treated in St Petersburg, including an Italian with a broken arm.

The bombing will be bad news for Russia’s tourist industry, particularly as the rail journey from Moscow to St Petersburg is one made by many foreign visitors. The trains are plush, tea is served from samovars and in the first-class sleepers there is even caviar on the breakfast menu.

Nikolai Patrushev, head of the Federal Security Service (FSB), who briefed President Putin on the derailment, said that the bomb was part of a pattern of violence that included attacks on security forces and officials in the North Caucasus region. “We have been able to significantly reduce the number of terrorist attacks,” he said, according to the Interfax news agency. “Nevertheless, the threat of extremism and terrorism has not been removed once and for all.”

There have been minor rebel attacks on Russian security forces recently, not so much in Chechnya as in neighbouring Ingushetia. But extreme Russian nationalists, perhaps wanting to smear the Chechens, might also be behind the latest bombing.

Interfax said that cables found at the Novgorod bomb site resembled those used to blow up a train heading from the Chechen capital, Grozny, to Moscow in 2005, when 42 people were injured. Russian nationalists, not Chechens, were subsequently convicted of that attack. The Echo of Moscow radio station said the cables were also similar to those used in a roadside bomb intended to kill market reformer Anatoly Chubais in 2005. It is a Russian nationalist rather than a Chechen rebel who is awaiting trial for that assassination attempt.

Chechen separatists have been largely inactive of late. After the Beslan tragedy of September 2004, when the seizure of a school by rebels led to a bloodbath in which 344 people died, the separatists seemed to have accepted that attacking civilians lost them world sympathy. They also lost their leader, Shamil Basayev, when he was killed by Russian forces in 2006.

Vladimir Churov, head of Russia’s Central Election Commission, assured viewers in an interview with NTV that Russia’s forthcoming elections — to the State Duma in December and for the presidency in March — would be peaceful.

In the run-up to elections in 1999/2000, Moscow and other cities were traumatised by massive apartment block bombings. The Kremlin blamed these on Chechen rebels and used them as justification for the second Chechen war.

No independent inquiry has even been held into these bombings and Alexander Litvinenko, poisoned in London last year, may have lost his life for daring to suggest that the FSB killed its own people in the bombings to ensure a frightened population stuck with the current leadership.

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