Moscow concert attack live updates: Suspects arrested; death toll rises to 115

Russia has arrested 11 people, including 4 suspected of carrying out the attack at a crowded concert venue in a Moscow suburb last night, the head of the country's Federal Security Service (FSB) has told President Vladimir Putin.
At least 115 people are now known to have been killed, Russia's Investigative Committee said this morning after men in camouflage broke into the concert hall and opened fire.
The terror group ISIS has claimed responsibility but did not provide proof of the claim.