The Istanbul police raided a suspected ISIS cell in the Kagithane district on the European side of the city, detaining two men identified as C.C. and I.D. who are said to be of Uzbek origin, the news agency Anadolu said.
Police seized two Kalashnikov rifles, ammunition magazines, 500 bullets, IS-related documents and digital materials. The suspected attacker of the Reina club, Abdulgadir Masharipov, an Uzbek national, was captured on January 16 in an Istanbul neighbourhood after more than two weeks on the run. He is currently under arrest.
Commentators had said that the capture of Masharipov and his interrogation would provide the authorities valuable intelligence on ISIS cells in the city.
The attack came during a New Year's Eve party at a nightclub and the victims included at least 15 foreign nationals, a Turkish minister had said. Two Lebanese, two Indians and five Saudi nationals were also among those killed, authorities confirmed on Sunday.
Around 700 people were at the Reina nightclub -- one of the city's most exclusive party spots -- when two men dressed as Santa Claus entered around 1.15 am and started firing at random, reported the Dogan news agency. Even before entering, they had killed a policeman and a civilian at the gate.