A team from Dhaka went to Nilphamari by helicopter on Saturday morning for the operation, RAB said in a statement.
In addition to the arrests, explosives have been recovered from the building, said ANM Imran Khan, RAB assistant director.
The RAB bomb disposal unit is at work on the scene.
The suspected hideout, located in the Majhapara area of Sonaray Union, was surrounded early on Saturday morning.
In addition to RAB, local police are also at the scene.