Rapid Action Battalion (Rab) arrested four suspected members of banned militant group Ansar Al Islam from Darus Salam in the city on Wednesday night.
The arrestees were identified as Amit Hossain alias Abul Kalam alias Sagar alias Action War, 38, Al Amin alias Tarik, 32, Shihab Uddin, 21, and Manikuzzaman alias Manik alias Ratan alias Ratan alias Cycle Man, 32.
Rab-2 sources said a special team conducted a raid between 6:20pm and 8:30pm at South Bishil area and arrested Amit Hasan from in front of Hotel Royal.
Based on his information, the special team arrested other three suspects from in front of a tea stall near Hazrat Shah Ali General Hospital under the same police station later that night, said Rab-2 media officer Md Abdullah Al Mamun.
The elite force recovered leaflets, books on extremism and other documents from their possessions.