Russia casts doubt on Islamic State responsibility for concert attack

Russia on Monday cast doubt on assertions by the United States that the Islamic State militant group was responsible for a gun attack on a concert hall outside Moscow which killed 137 people and injured 182 more. In the deadliest attack inside Russia for two decades, four men burst into the Crocus City Hall on Friday night, spraying people with bullets just before Soviet-era rock group Picnic was to perform its hit "Afraid of Nothing".