Russia has charged four men it says attacked a Moscow concert hall and killed at least 137 people.
Three were marched bent double into a Moscow court while the fourth was in a wheelchair.
All 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”.
Video showed three of them being marched by masked police into Basmanny district court in the Russian capital.
All appear to have been beaten – videos of brutal interrogation sessions were apparently leaked by Russian security forces, and reports suggest at least one had suffered electric shocks.