Russia on Monday cast doubt on assertions by the United States that the ISIS militant group was responsible for a gun attack on a concert hall outside Moscow which killed 137 people and injured 182 more.
In the deadliest attack inside Russia for two decades, four men burst into the Crocus City Hall on Friday night, spraying people with bullets.
Four men, at least one a Tajik, were remanded in custody for terrorism. They appeared separately, led into a cage at Moscow's Basmanny district court by Federal Security Service officers.
ISIS has claimed responsibility for the attack, a claim which the United States has publicly said it believed, and the militant group has since released what it says is footage from the attack. US officials said they warned Russia of intelligence about an imminent attack earlier this month.
But President Vladimir Putin has not publicly mentioned the group in connection with the attackers, who he said had been trying to escape to Ukraine.
Putin said some people on "the Ukrainian side" had been prepared to spirit the gunmen across the border. Ukraine has denied any role in the attack and President Volodymyr Zelenskiy has accused Putin of seeking to divert blame for the concert hall attack by referring to Ukraine.
Russia's Foreign Ministry spokeswoman, Maria Zakharova, called into question US assertions that ISIS, which once sought control over swathes of Iraq and Syria, was behind the attack.
"Attention - a question to the White House: Are you sure it's ISIS? Might you think again about that?" Zakharova said in an article for the Komsomolskaya Pravda newspaper.
Zakharova said the United States was spreading a version of the "bogeyman" of ISIS to cover its "wards" in Kyiv and reminded readers that Washington supported the "mujahideen" fighters who fought Soviet forces in the 1980s.
Unverified videos of the suspects' interrogations circulated on social media. One of the suspects was shown having part of his ear cut off and stuffed into his mouth.
One man, a Tajik named Dalerdzhon Mirzoyev, leaned against the glass cage as the terrorism charge was read out. Saidakrami Rachabalizoda, his ear in bandages, sat.
Muhammadsobir Fayzov, appeared in gaping hospital clothes and sat in a medical chair, his face covered in cuts. Shamsiddin Fariduni, his face bruised, stood.