Ya, direct warning to the Russian government followed up by the advisory. Apparently it was dismissed by Russia as a hoax for internal interference. Will be interesting to see what actually comes out.
Moscow attack: Did Russia ignore US 'extremist' attacks warning?
The attack on a concert hall in Moscow raises difficult questions for Putin at a time of global mistrust.
www.bbc.com
There are channels through which intelligence is shared between countries - even those that are not allies - especially when it relates to possible attacks on civilians.
But the problem is that Moscow dismissed the warnings.
Three days before the attack, Russian President Vladimir Putin addressed the board of Russia's Federal Security Service (FSB), whose job is to defend the country. The top priority, he told the assembled leaders of the security service, was to support what he called the special military operation - the official phrase for the full-scale invasion of Ukraine.
He claimed that Ukraine had switched to what he called "terrorist tactics". He also spoke directly to what he said were "provocative statements" from the West about potential attacks within Russia. He said the warnings "resemble outright blackmail and the intention to intimidate and destabilise our society".