At least ten people were killed and three others injured in an explosion at a railway station in Russia, the interior ministry confirmed Sunday.
Preliminary reports said three people died and ten others were injured in the blast, which took place at the metal detection arches of the station entrance in Volgograd, a city near the North Caucasus region, Xinhua reported.
Police are working on the site to investigate the incident.
In October, a female suicide bomber blew herself up in a bus in Volgograd, killing seven people and injuring many.
President Vladimir Putin in September warned that the situation in North Caucasus remained a challenge for state security. He urged all law enforcement departments to be mobilised to maintain law and order and peace in the region.