Law enforcers say militant outfit New JMB is changing their modus operandi, going by raids over the past two years.
The recent raid in Sitakunda, codenamed Operation Assault 16, revealed intriguing facts about the change in the bombs used by the militants.
Conspicuous wiring used by a tenant raised the suspicion of the landlord, who later discovered they were used in explosive timers. He alerted the police which led to the Sitakunda raid.
Based on recent information, police believe JMB has indeed evolved their arsenal. Bombs are no longer of rudimentary design but are becoming more lethal.
An active component of the latest bombs is ammonium nitrate, an explosive mixture used to blast stone in quarries.
According to a member of the Counter Terrorism and Transnational Crimes (CTTC) unit of the police, ammonium nitrate is imported from India through Chapainawabganj as an industrial material and is strictly regulated.
The CTTC official also disclosed that the company which imports the explosive material has also been identified.
CTTC suspect Mizanur Rahman alias Boma Mizan is New JMB’s demolitions expert. However, they are unsure whether it is Mizan who has adapted his methods or whether someone new is designing the new bombs.
Mizan’s signature bombs used gunpowder, an assortment of chemicals and a pin to produce a crudely-made grenade.
The recent bombs are being improvised and improved upon with ammonium nitrate and a new auxiliary switch that allows for delayed explosions.
During Operation Twilight at Sylhet, army spokesperson Brig Gen Fakhrul Ahsan told the media that the bombs discovered at Atia Mahal – the militant den – surprised the law enforcers.
He noted that the shockwave, when the bombs were defused, could be felt about two kilometres away.
According to the Bomb Disposal Unit (BDU), the bombs recovered from the Ashkona militant den in December last year were much more powerful than any explosives recovered before.
Additional Deputy Commissioner (BDU) Rahmatullah Chowdhury said the timers on the latest bombs were set to go off after four or five minutes.
Police suspect the two blasts outside the Sylhet den were time bombs, and said they would know more after the operation.