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”.The four were named by Russian authorities as Dalerdzhon Mirzoyev, Saidakrami Murodali Rachabalizoda, Shamsidin Fariduni and Muhammadsobir Fayzov.

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.

The men the court identified as Mirzoyev and Rachabalizoda had black eyes and the latter’s ear was heavily bandaged – reportedly from it being partially severed during his arrest.