The elite police unit said it detained JMB Dhaka district chief Abdul Baten alias Khairul Islam alias Mamunul Haque, 28, and three of his accomplices during separate raids in Dhaka's Khilgaon and Fakirarpul areas on Wednesday and early hours on Thursday.
The three others have been identified as Monir Molla, 29, Md Golam Kibria alias ‘Akter’, 62, and Md Rumman Khan, 27.
RAB media wing chief Mufti Mahmud Khan said in a media conference Monir was in charge of the outfit’s activities in Gulshan and Badda.
Baten was an associate of Md Nayeem, a JMB militant named in India’s Burdwan blast investigation in Bangladesh, Khan said.
Citing initial interrogation, he said Akter and Rumman, arrested from Fakirarpul, arrived in Dhaka on Wednesday night from Chittagong to carry out attacks.
A weapon, ammunition, petrol bomb, explosives, improvised explosive devices (IED) and jihadi literature were found on them, he added.