Moscow’s Basmanny Court has arrested three more suspects allegedly connected to Friday’s deadly terrorist attack on Crocus City Hall, the court’s press service has reported. The detainees will remain in custody until at least May 22.

According to The Iran Project,A day earlier, the same court arrested four men who investigators believe carried out the shooting spree, which has left at least 133 people dead and scores wounded.

The three suspects – Aminchon Islomov, Dilovar Islomov and their 62-year-old father Isroil Islomov – are accused of being involved in organizing the terrorist act, according to Russia’s Investigative Committee.

In an application to the court shared on the service’s Telegram channel, investigators claimed that one of the gunmen, Shamsidin Fariduni, is believed to have recruited Aminchon Islomov in January to join his organized terrorist group, with the goal of committing a terrorist act. No later than on March 11, he is thought to have also recruited Dilovar Islomov, investigators say, demanding the immediate arrest of the two brothers as well as their father.

According to Russian media outlets, Dilovar Islomov is believed to have been the last owner of the white Renault which was allegedly used as a getaway vehicle by the terrorists as part of their plan. However, no official details as to how the three relatives were connected to the incident have yet been made public.  

On the evening of March 22, a group of gunmen armed with assault rifles attacked the Crocus City music hall in the town of Krasnogorsk, on the western outskirts of Moscow, just before a concert by the rock band Picnic was due to start. The venue, with an estimated capacity of 7,500, was almost full at the time of the attack. The terrorists killed the guards, shot concert-goers on sight then started a fire that quickly spread throughout the building.

Eleven people, including four terrorists who were directly involved in the deadly shooting, were detained in connection with the massacre, the Russian domestic security service, the FSB, said in a statement on Saturday. Seven of them have since been arrested by the court.