Radio Liberty’s Tajik Service, known locally as Radio Ozodi, reported on April 17 that Russian authorities have arrested a dual Tajik–Russian national in connection with the March 22 terrorist attack on the Crocus City Hall concert venue in Krasnogorsk that left more than 140 people dead.

Radio Ozodi reports that a court in the city of Tver said on April 16 that the suspect, identified only by his surname, Ashourov, has been placed under arrest for illegally registering two foreign nationals at his residence.

The Islomov brothers -- Aminjon and Dilovar -- are currently in Russian custody along with their father, Isroil Islomov, for allegedly aiding the suspects who are accused of carrying out the deadly attack on the Crocus City Hall concert venue.

Prior to Ashourov's arrest, Russian authorities had arrested 10 Tajik citizens and a Kyrgyz national in connection with the attack, Russia's worst terrorist attack in two decades. Responsibility was claimed by an offshoot of the Islamic State (IS) terrorist group.

Russian investigators have said the assault was carried out by four men, all Tajik nationals. Other detainees are being held for aiding and abetting the attackers.

On April 17, a Moscow court upheld the arrest of the Kyrgyz suspect, Alisher Kasimov, who had appealed against his arrest.

"The ruling of Moscow's Basmanny district court of March 26, 2024, has been upheld, and the appeal has been dismissed," a Moscow court official was quoted as saying by Russian state media.

A similar ruling was passed by the same court for Aminjon Islomov, who had also appealed his detention. The Islomovs have been charged with providing an apartment and vehicle to the attackers, and transporting cash for them.  They have denied the accusations.

The Basmanny court also said that another suspect, Lutfulloi Nazrimad, a 24-year-old Tajik national, filed an appeal on April 15 against his arrest.

Nazrimad was taken into custody on March 23 with investigators claiming he knew about the planned terrorist attack and helped the attackers. In a closed-door hearing on March 29, the court extended Nazrimad's detention until May 22.

Several Tajik suspects showed signs of abuse when they appeared in court in Moscow following the attack.

The four accused gunmen had bruised and swollen faces and showed other signs of having been severely beaten.  There were unconfirmed reports that one of them had his ear cut off during his arrest.