Russian President Vladimir Putin attends an expanded meeting of the Prosecutor General's Office board in Moscow, Russia, Tuesday, March 26, 2024.

Video. Russian FSB says US, UK and Ukraine behind Moscow attack

The director of Russia's Federal Security Service (FSB), Alexander Bortnikov, said on Tuesday that the US, UK and Ukraine were behind the Moscow concert hall attack that killed at least 139 people on Friday - despite repeated claims of responsibility by Islamic State.