So... ISIS HAS claimed responsibility AND:
"Putin dismissed US warnings about a potential terror incident as 'blackmail' just 3 days before concert hall attack
Earlier this month, the US embassy in Russia issued a security alert warning about a potential terror attack in Moscow and urged people to avoid crowds, monitor local media for updates, and be aware of surroundings.
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"The Embassy is monitoring reports that extremists have imminent plans to target large gatherings in Moscow, to include concerts, and U.S. citizens should be advised to avoid large gatherings over the next 48 hours," the March 7 security alert said.
Putin addressed the warnings a couple weeks later, criticizing the warning three days ago as "provocative."
Per TASS, the Russian president said on March 19 the aim of "the recent provocative statements of a number of official Western structures about the possibility of terrorist attacks in Russia" was harming Russian society.
"All this resembles outright blackmail and the intention to intimidate and destabilize our society," Putin said, according to state media reporting on his remarks.
The US embassy issued another alert on Friday saying it was "aware" of the attack and urged Americans to avoid the area.
"We strongly condemn the horrendous attack carried out at a concert hall in Moscow," Russia's foreign ministry said in a statement. "We express our deepest sympathies with the families of the victims."
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