If a warning from the US didn't get the attention of Russian security officials ahead of last month's horrifying terrorist attack in Moscow, a direct warning from Iran ought to have done. According to Reuters, Iran warned Russia of a possible "terrorist operation" in Russian territory after Iranian officials gained information from suspected terrorists linked to January's twin bombings in Kerman. The Islamic State militant group ISIS-Khorasan (ISIS-K) has claimed responsibility for both the bombings, which killed nearly 100 people in the deadliest attack in Iran since the 1979 Islamic Revolution, as well as the attack on Moscow concert venue Crocus City Hall, which claimed at least 144 lives in the deadliest attack inside Russia in 20 years.
Russian spy service chief Sergei Naryshkin has said the US warning, dated March 7 and reportedly derived from talk among ISIS-K operatives, was too general to be of use, per Sky News. While Moscow may have been distrustful of the US intelligence, "it is harder ... for Russia to dismiss intelligence from diplomatic ally Iran on the attack, which has also raised questions over the effectiveness of Russian security services," per Reuters. Iran informed Russia of the alleged plans days before March 22 attack, sources tell the outlet. It notes no specific details were provided about location or timing, but the warning of a possible major terrorist attack inside Russia was clear.
One source said ISIS-K members held by Iran admitted they'd been preparing for an operation in Russia and some members had already traveled there. "Iranian authorities fulfilled their obligation to alert Moscow based on information acquired from those arrested terrorists," a senior security official tells Reuters. Asked about the report on Monday, however, Kremlin spokesperson Dmitry Peskov said, "I do not know anything about this." Russia has publicly linked Ukraine and the West to the attack, though US officials say there is no evidence to support the claim. Russia's Federal Security Service said Monday it had arrested four foreign citizens who "were directly involved in the financing and supply of terrorist means," per the Telegraph. The four alleged gunman are already in custody and showing signs of torture. (More Russia Crocus shooting stories.)