Russian authorities say that they have taken into custody two suspects in connection with a purported plot to carry out terrorist attacks in St. Petersburg on New Year's Eve that was foiled in part based on an intelligence tip from the United States.
The Federal Security Service (FSB) announced last weekend that the men were detained on December 27 based on information from their "American partners."
Russian President Vladimir Putin on December 29 spoke by telephone with U.S. President Donald Trump to thank him for the intelligence.
A White House readout of the call stated Putin appreciated "information the United States provided that helped foil a potential holiday terrorist attack in Russia."
Both presidents, the readout said, were "committed to continuing counterterrorism cooperation between the two countries."
Trump later tweeted on December 31 that the "great & important coordination" between the United States and Russia saved "many lives."
In a statement, the local court service identified the suspects as 22-year-old Nikita Semyonov and 23-year-old Georgy Chernyshov.
A St. Petersburg shopping center and a cathedral where many tourists flock were the alleged targets, the local Fontanka news website reported, citing an FSB source.
The pair had allegedly sent pictures to the Islamic State extremist group confirming the targets.
A video released by the FSB of the raid on the suspects' residence showed the arrest of men bearing a Slavic appearance inside an apartment containing munitions, knives, electrical cables, and black clothing, AFP reported.
In October and in 2017, the United States had also shared information about terrorist plots with Russian officials, state TASS news agency reported.