Russia train crash 'caused by bomb'

A bomb blast caused the Russian train crash in which at least 26 people were killed, intelligence officials say.

The Nevsky Express derailed with nearly 700 on board as it ran through remote countryside between the capital Moscow and the second city, St Petersburg.

Investigators found "elements of an explosive device" at the scene of Friday's attack, a statement said.

Officials said a second, less powerful device went off on Saturday near the site of the first, but no-one was hurt.

There was no immediate confirmed claim of responsibility for the blast on Friday evening, which hit a train popular with government officials and business executives at peak travel time.

"Criminology experts say, on the basis of preliminary information, that an improvised explosive device, equivalent to 7kg (15 lb) of TNT, had gone off," said Alexander Bortnikov, head of Russia's domestic intelligence service.