Rapid Action Battalion (Rab) members detained three people for their alleged involvement with the killing of ward-level Awami League leader Jahangir Alam in Dhaka 17 days back.
Rab nabbed the trio, whose identities could not be known immediately, from different parts of the capital.
Jahangir Alam, 45, one of the president candidates of ward no-28 unit of AL, was shot dead in front of his West Agargaon house while he was getting down from his car on August 9.
Among the detainees, Rab identified Naeem as the main killer who shot Alam in his chest, Mufti Mahmud Khan, director of the legal and media wing of Rab, told The Daily Star.
The victim was also president of Agargaon Momota Bahumukhi Samabaya Samity.
Rab arrange a press briefing to inform the media detail about the operation later in the day.