Seven militants are killed in Dagestan 's capital , Makhachkala , Russian state media report . Investigators say the counterterror operation followed an attack Friday , state media say . Security has been stepped up in Russia ahead of the Winter Olympics next month . TL;DR Concerns about security in Russia were heightened after twin bombings on public transit that killed more than 30 people in the southern city of Volgograd at the end of last month . A suicide bomber kills at least seven people and wounds dozens more outside a police station in Russia's southern city of Volgograd on Saturday.
Seven militants are killed in Dagestan 's capital , Makhachkala , Russian state media report . Investigators say the counterterror operation followed an attack Friday , state media say . Security has been stepped up in Russia ahead of the Winter Olympics next month . TL;DR A suicide bomber kills at least seven people and wounds dozens more outside a police station in Russia's southern city of Volgograd on Saturday.