Russian authorities said they had detained 11 people in connection with a terrorist attack on a concert hall in a Moscow suburb‚ as the death toll from the Friday night assault rose to 115‚ investigators said. Among those taken into custody were four people who prosecutors said played a direct role in the violence‚ in which gunmen shot audience members at close range and set off smoke bombs. Islamic State‚ the Islamist militant group‚ claimed responsibility in a statement on Telegram....