Reports: Islamic terrorists or extremist nationalists possibly behind Russian train blast

Islamic terrorists or "pro-fascist" extremist nationalist groups are being considered as the possible culprits behind a bomb that derailed a passenger train south of Moscow over the weekend, Russian news reports said Tuesday.

Citing unnamed prosecutors' officials, the ITAR-Tass and Interfax news agencies said that investigators have also not ruled out nationalist groups from Russia's troubled Caucasus region as being behind the incident on Sunday that injured 15 people, mainly passengers on the train traveling from the Chechen capital Grozny to Moscow.

Investigators found a crater on the tracks at the site of the blast and found wires attached to the right rail.

The blast occurred just hours before President Vladimir Putin marked the Day of Russia holiday with a reception and awards ceremony in the Kremlin.

Russia has been hit by a series of terrorist attacks in recent years, which have been mostly blamed on Chechen separatists.

AP