Overview

• A total of 21 people have been arrested in Russia and Tajikistan in connection with the Moscow concert hall attack that killed 144.
• Russia has detained 12 individuals, including a Tajik citizen, with nine facing pre-trial detention.
• Tajikistan's state security service has detained nine people for suspected contact with the attackers.
• Russia alleges Ukrainian and Western involvement in the attack, claims dismissed by Ukraine and the West.
• The Islamic State has claimed responsibility for the attack, its deadliest on European soil.