International

Kuvvatov, who was head of the "Gruppa 24" opposition movement, had been living in exile in Turkey. He was killed with a single shot to the head in front of his wife and children in the Fatih district of the city, after eating dinner at a house in the area. The assailants then fled the scene.

The detentions took place based on the accounts of Kuvvatov's relatives, eyewitnesses of the shooting and CCTV footage, as part of a probe conducted by the İstanbul Police Department Counterterrorism Unit.

Kuvvatov's "Gruppa 24" movement was declared an "extremist organization" and banned by Tajikistan's Supreme Court last October. Tajik law enforcement authorities wanted him for a number of crimes, including extremism, corruption and hostage-taking but Turkey had declined to extradite him.