Moscow attack: Russian court charges four men with act of terrorism
Russian officials have claimed, without evidence, Ukrainian involvement. Kyiv says the claim is "absurd".
Russia has charged four men it says attacked a Moscow concert hall and killed at least 137 people.
All four appeared to have been beaten and one was brought to court in a wheelchair. They were charged with committing an act of terrorism.
The Islamic State group, or IS, said it carried out Friday's outrage at Crocus City Hall and posted video evidence.
Russian officials have claimed, without evidence, Ukrainian involvement. Kyiv says the claim is "absurd".
The graphic video released by IS, showing attackers firing on the crowd inside the concert hall, has been verified as genuine by the BBC.
However, no Russian official has acknowledged the claim, and Kremlin spokesman Dmitry Peskov said in a news conference on Monday that it was inappropriate to comment on it until the investigation had been completed.
He also said that because of the tense international situation there was little collaboration between countries on fighting terrorism.
France has raised its terror alert to the highest level, with President Macron saying on Monday that the Islamic State group behind the Moscow attack had also recently been targeting France.
Mr Macron also warned Russia against trying to exploit the attack to blame Ukraine, describing such a move as cynical and counter-productive.
The four suspects were named by Russian authorities as Dalerdzhon Mirzoyev, Saidakrami Murodali Rachabalizoda, Shamsidin Fariduni and Muhammadsobir Fayzov.