Russia’s domestic intelligence service, the FSB, has detained further people it suspects of having been involved in the terrorist attack on the Crocus City Hall event centre in north-west Moscow more than a week ago. Four foreign nationals who were directly involved in financing and equipping the terrorists were detained in the Russian republic of Dagestan in the North Caucasus, the FSB announced in Moscow on Monday. The terrorist militia Islamic State has claimed responsibility for the attack. State media also showed a video released by the FSB in which an unrecognizable man says that he hand…