Russian security agency says suspects detained in the Caucasus are linked to Moscow attack

Russia’s top security agency says it has broken up what it called a “terrorist cell” in southern Russia whose members had provided weapons and cash to suspected attackers of the Moscow concert hall. The Federal Security Service, or FSB, said that it arrested four suspected members of the cell in the Russian province of Dagestan in the North Caucasus on Sunday. The agency alleged that the suspects were involved in channeling funds and providing weapons to the gunmen who attacked the concert hall on Moscow’s western edge on March 22, killing 144 people in the deadliest attack on Russian soil in two decades.