A shrapnel-filled bomb exploded near a police station in Russia's troubled Dagestan region on Thursday, killing at least four people and injuring 18 others, officials said. The bomb, attached to a motorcycle or scooter parked near the police station in the city of Khasavyurt exploded at about 10:00am, the press service of the regional Interior Ministry said. The blast killed two police officers and two passersby—a woman and a 5-year-girl, the ministry said. One of the officers, the head of a branch of the city police that provides security to private companies and state-run enterprises, was killed in his office,...