The Russian authorities on Saturday announced the arrest of four individuals suspected of setting a suburban Moscow concert on fire and killing at least 143 people, in one of the worst terrorist attacks to shake Russia in President Vladimir Putin’s nearly quarter-century in power.

The suspects, identified by Russian authorities as Dalerdzhon Mirzoyev, Saidakrami Rachabalizodu, Shamsidin Fariduni, and Muhammadsobir Fayzov, faced trial at the Basmanny Court in Moscow. 

The court proceedings were conducted in private, and Fayzov, who reportedly filmed the attack at the concert hall in Krasnogorsk, appeared at the hearing on a stretcher, struggling to communicate, according to reports.

The court has ordered the detention of all four suspects until at least May 22.

Earlier reports indicated that one of the individuals charged with perpetrating the terror attack is a Tajik national. All four suspects hail from the former Soviet republic of Tajikistan and have been residing in Russia on either temporary or expired visas.

The concert venue, with an estimated capacity of 7,500, was nearly at full capacity when the terrorists launched their attack. This tragic incident occurred just before a performance by the Russian rock band Picnic.

Based on mobile phone footage and eyewitness testimonies, at least five gunmen, clad in military-style attire and armed with assault rifles, initially targeted unarmed security personnel at the venue’s main entrance. 

Subsequently, they indiscriminately fired at the fleeing and panic-stricken crowd of concertgoers. Upon entering the concert hall, the attackers set fire to rows of chairs, leading to a rapid engulfment of the building, including its roof.

In a televised address, Russian President Vladimir Putin condemned the attack, and said that Ukraine facilitated a passage for the perpetrators to cross the border. He pledged to uncover and punish all those involved in this heinous act and declared March 24 as a national day of mourning.

(With agency inputs)