There is a strong possibility of terror attacks around the Sochi Winter Olympics, a Whitehall source has told ITV News. The threat level of an attack before or during the games is substantial, they added.
Video of a terrifying raid by the Russian security services on suspected Islamist militants has been released by the authorities.
For years Dagestan has been the scene of a separatist struggle. Now it is home to Islamist militants who have vowed to target the Games.