A criminal investigation has been opened...

The blast occurred on a line in the vicinity of an urban beach in Makhachkala. There were no other causalities.

The rail track was not damaged during the blast.

The incident comes two months after the luxury high-speed Nevsky Express between Moscow and St. Petersburg was derailed by an explosion, killing 27 passengers and injuring more than 90.

MAKHACHKALA, FEBRUARY 11 (RIA Novosti)