Police arrested at least 25 leaders and activists of BNP from different areas of the district since Tuesday afternoon.
The BNP men were nabbed on charge of planning to carry out subversive activities, said Md Shahidullah, officer-in-charge of Sadar Model Police Station.
Of them, three each from Chatak, Jamalganj, Doarabazar and Biswambarpur upazilas, two each from Jagannathpur, Dirai and South Sunamganj upazilas while one each from Dharmapasha and Shalla upazilas, said UNB.