The attack, which left 150 dead, marks the deadliest incident of its kind in Russia for two decades.

The Federal Security Service (FSB) announced the arrests, stating that all four perpetrators were captured while attempting to flee towards the Ukrainian border. 

The FSB further alleges the attackers possessed connections within Ukraine, a nation with whom Russia has been embroiled in conflict for the past two years.

While details remain unclear, the FSB asserts some of the attackers sought escape across the Russia-Ukraine border.  The statement, relayed through state-run media, additionally suggests the assailants had established contacts within Ukraine.

Unverified reports from Russian Telegram channels, including Baza (known for its ties to security services), and a lawmaker allege some of the suspects hail from Tajikistan, a central Asian nation.

Official investigations are ongoing, and no definitive conclusions have been drawn regarding the attackers' motives or affiliations. (ILKHA)