Attack Suspected in Russian Train Crash that Killed 25

Officials in Russia say a train crash that killed at least 25 people late Friday may have been caused by a bomb.

Prosecutors said Saturday they have begun a criminal investigation that could result in terrorism charges, but did not identify suspects.  Investigators near the town of Bologoye are looking for clues into what caused the deadly incident on the Nevski Express high-speed luxury train.

Rescue workers are sifting through the wreckage in search of 18 missing people and have said that the death toll is likely to rise. 

Russian news agencies report a small crater was found at the site of the wreck. Witnesses said they heard an explosion.

More than 50 passengers were injured when the train derailed between Moscow and St. Petersburg.

The White House released a statement saying it is deeply saddened by the terrible loss of life and injuries.

A health ministry official said earlier that 39 people were killed in the crash, but authorities said Saturday the official was given the wrong information. 

Reports say a bomb blast on the same line in 2007 derailed a passenger train and injured dozens.  Authorities suspected that Chechen separatists caused the attack.

Russia has also been plagued by deadly accidents resulting from deteriorating Soviet-era infrastructure.