The elite police unit earlier detained Mawlana Mainul Islam, ‘the chief coordinator of AQIS in Bangladesh’, his adviser Mawlana Zafar Amin and ten activists of the terror outfit.
Massive amounts of explosives, bomb-making materials, weapons and training manuals were found in their possession.
The AQIS had claimed responsibility for hacking bloggers Avijit Roy and Ananta Bijay Das to death.
Mainul Islam, 35, was previously involved with banned radical group Harkat-ul-Jihad-al-Islami, Bangladesh (HuJI-B), according to RAB.
It informed the media about detaining the AQIS men in an SMS.
RAB’s Media Wing Director Mufti Mahmud Khan provided details in a press brief held at its Uttara headquarters on Thursday noon.
“They were meeting in Dhaka to plan an attack on the capital after Eid. They rented a house in Mirpur to carry out their plans.
“Most of them are from Barisal or Khulna.”
A team by RAB-4 conducted the operation at Sadarghat at 6:30am Thursday, after receiving a tip-off, he said.
Mainul Islam, Zafar Amin aka Salman, members of AQIS in Bangladesh – Sayeed Tamim, 20, Md Mosharraf Hossain, 19 and Abdur Rahman Bepari, 25, were detained from there.
Activists Alamin aka Ibrahim, 28, Md Mojahidul Islam aka Nakib aka Sharif, 31, Ashraful Islam aka Abul Hasem, 20, Rabiul Islam aka Hasan, 28 and Md Jabibullah, 26, were later held based on information divulged by those detained before.
RAB then raided a house at Mirpur’s Bardhanbarhi to detain Md Shahidul Islam aka Sagar, 29, and Altaf Hossain aka Al Mamun, 26.
One kilogram of sulphur, 1.5 litres of sulphuric acid, 400 grams of potassium chloride, 550 marbles, extremist literature, 16 mobile phones, four nunchakus, five knives, one machete, two Chinese axes, a carton of matches, 15 explosive devices and ten small knives – were found in the house.
Those detained were once involved with HuJi, said the RAB spokesperson.
Top Huji leader Mawlana Mufti Moinuddin aka Abu Zandal aka Masum Billah, on death row for the bomb attack on a British high commissioner, has been contacting these men from Kashimpur Jail using cell phones and letters, he said.
The operatives planned to come out as ‘Dawat-e-Tabligh’ and then as ‘313 Badar Sainik’ based on his tips.
“The detainees have told us their main goal was to join AQIS after al-Qaeda’s full expansion in Bangladesh.”
They have been trying to become ‘more active’ after seeing the ‘video message by al-Qaeda chief Ayman al-Zawahiri’ and ‘activities of the Islamic State’, said the RAB spokesperson.
The radicals, who have been ‘under significant pressure’ due to security activities, were using new methods of recruiting members, said the RAB spokesperson.
They have been working to ‘invite’ new members through Facebook, Twitter, Viber and Whatsapp.
Dawat-e-Tabligh used three steps for recruitment. Those who liked its Facebook page would be given the title of ‘Dwin Kayemer Sathi’, which translates to ‘Friend in practicing faith’.
Those who vow their allegiance would be called ‘Bayate Fi Sabilillah’, meaning who preaches for the cause of Allah, in the second step of recruitment.
The third step is called ‘Shahidi Kafela’. Those with ‘strong will’ and prepared to be ‘martyred’ in Jihad reach the third tier, according to RAB.
Twenty individuals recruited for ‘313 Badar Sainik’, the organisation the detainees thought of making, took part in a 20-day training session in Bogra.
‘Training manuals’ from that session were recovered, said RAB in the briefing.
An individual called ‘Rafique’ funds ‘313 Badar Sainik’ and uses Facebook from Saudi Arabia and Dubai.
“They were also planning to free HuJI leader Mawlana Moin Uddin by sawing off sewerage grills at Dhaka Central Jail.”