Russia has charged four men it claims attacked a Moscow concert hall, killing at least 130 people and wounding more than 180. 

The men, who showed signs of severe beatings, were marched handcuffed and bent double into a court in the Russian capital on Sunday. One appeared to be barely conscious during the hearing.

All were charged with terrorism, which carries a sentence of life imprisonment. All pleaded guilty. 

The Islamic State (IS) terror group claimed responsibility for the attack on the Crocus City Hall on Friday, a claim corroborated by US intelligence.  

Russian officials have alleged, without evidence, that Kyiv was involved, with the assailants supposedly headed to Ukraine after the shooting. Ukraine said the claim is “absurd”. 

The men were officially identified as citizens of Tajikistan. They were named as Dalerdzhon Mirzoyev, Saidakrami Murodali Rachabalizoda, Shamsidin Fariduni and Muhammadsobir Fayzov.

All appeared in court bloodied and bruised. 

Rachabalizoda's ear was bandaged after it was reportedly cut off during his arrest, and Mirzoyev had a torn plastic bag around his neck. Both had black eyes and cuts and bruises on their faces. 

Fariduni's face was severely swollen. Fayzov was brought into the court in Moscow's Basmanny district in a wheelchair. One eye appeared to be missing and he was wearing a hospital gown. 

The men were remanded in custody for two months at the court hearing, though their condition raised questions about whether they spoke freely. 

Russian media reported the men were tortured during interrogation by the security services. 

The hearing came as Russia observed a national day of mourning for the attack that killed 137 people. The IS-claimed assault is the deadliest attack by any group in Russia since the 2004 Beslan siege. 

On Friday, gunmen dressed in combat gear stormed the Crocus City Hall in Moscow. They sprayed the crowds with gunfire and threw explosives, leaving the venue smouldering under a collapsed roof. 

Events across the country were cancelled on Sunday, flags were lowered to half mast and television entertainment and advertising were suspended, state news agency RIA Novosti reported. 

Foreign embassies in Moscow have voiced their solidarity with the victims of the attack.

The raid was a major embarrassment for Putin, happening days after he cemented his grip on the country for another six years in a vote that followed the harshest crackdown on dissent since Soviet times.

Some commentators on Russian social media questioned how authorities, who have relentlessly suppressed opposition activities and muzzled independent media, failed to prevent the attack. 

US intelligence officials said they warned Moscow of a looming attack by IS in the weeks leading up to the bloodbath.

The terror group, which fought against Russia during its intervention in the Syrian civil war, has long targeted Russia. 

In a statement posted by the group’s Aamaq news agency, the IS Afghanistan affiliate said it had attacked a large gathering of “Christians” in Krasnogorsk.

The group issued a new statement on Saturday on Aamaq, saying the attack was part of its ongoing war with countries it claims are fighting against Islam.

In October 2015 a bomb planted by IS downed a Russian passenger plane over Sinai, killing all 224 people on board, most of them Russian holidaymakers returning from Egypt.

The group, which operates mainly in Syria and Iraq but also in Afghanistan and Africa, has claimed responsibility for several attacks in Russia’s volatile Caucasus and other regions in past years.

Euronews