Remote-controlled bombs now in the hands of militants

In the wake of the recovery of several bombs in Dhaka and on its outskirts in recent days, police say militants have now started making remote-controlled bombs. 

Police also recovered a remote device from a pressure-cooker bomb thrown at a tea shop in Ashulia. Two weeks later, they said another pressure-cooker bomb found in a field in Bangram Union in Savar was also remote-controlled.

One possible source for this development is Nazmul Hasan aka "Bomaru" (Bomber) Mamun. Police officials say he was trained by bomb makers who were part of the neo-Jamaatul Mujahideen Bangladesh (neo-JMB).

Mamun used to make pressure cooker and pipe bombs 10 years ago. Police said at the time that the 2017 bomb blast at Hotel Olio, which resulted in the death of a “suicide bomber”, was caused by two pressure cooker bombs made by Mamun.

In that period, a series of operations killed the alleged neo-JMB bomb makers. Mamun had been in prison since then, but was released after the Awami League government fell amid a mass uprising in August 2024.

Officials say he put together another team and started making bombs again. Now the matter of remote control being added to pressure cooker bombs has raised fresh concerns for police.

Investigators say Mamun and his disciple Arif alias Imran were involved in an incident in which a bomb under construction exploded at a madrasa in Keraniganj last December.

Mamun allegedly stabbed a police officer and fled with a bomb bag during a search in Jatrabari in February. The two are said to have set off an explosion at a Shiva temple in Cumilla in March and detonated a bomb during a police search in Sayedabad that same month.

Police have been looking for Mamun since then. In July, police said that Mamun and Arif were also involved in the incident of leaving a “pipe bomb” beneath an umbrella under the Motijheel Metro Station during the Hindu “Ulto Rath Yatra” event and leaving a pressure cooker bomb at a tea shop in Ashulia’s Charabagh.

After Arif was arrested on Tuesday evening, police conducted a raid on his hideout in Savar’s Shyampur.

The raid continued from evening until 2:45am, with officers surrounding the house. At that time, police's Counter Terrorism and Transnational Crime (CTTC) unit reported the recovery of several pipe bombs and bomb-making chemicals from the house.

In a case filed in connection with the raid, police also wrote about the recovery of remotes and controllers.

The case states, “Different types of liquid chemicals, chemical powder, potassium nitrate, cotton buds mixed with gunpowder, electrical wires, detonators, remotes and controllers, pipe bomb debris, various equipment and several books related to a holy war were recovered from Arif’s rented house in South Shyampur.”

Following the overnight operation on Tuesday, the police reported finding another “pressure cooker” bomb inside a drum lying in a field in front of the Laltek Ghodra Mosque in Savar’s Goperbari on Wednesday.

Locals grew suspicious after they saw the blue drum lying there since Tuesday night. When people saw a pressure cooker wrapped with electrical tape inside the drum, they took it out and placed it in the field. Someone removed the drum at a later time.

Both the bombs were recovered and deactivated by members of the Bomb Disposal Team of the CTTC.

A CTTC official said that both of them were remote-controlled pressure cooker bombs.

The official said, “The pressure cooker bomb that was thrown at the tea shop in Ashulia’s Charabagh was in a travel bag. We found a remote in that bag. That type of remote is used for the electric locks used in motorcycles. The bomb could have been detonated with that remote.”

The official said that the pressure cooker bomb thrown at the Laltek Ghodra Mosque ground was also confirmed to be remote-controlled. However, its remote was not found.

The CTTC official said, “We are sure that the bomb that was thrown at the mosque grounds had a remote control, but we did not find it. This is because they first left the pressure cooker bomb and some other items in a drum behind the mosque around 1am.

“Then, locals became suspicious and looked into the drum and saw a pressure cooker with a broken handle. They took it out and put it in the field. The bomb remained in the field overnight.

“Around 6am, some people came and took away the blue drum. We think that when the raid was going on at Arif’s rented hideout in Savar’s Shyampur, they may have left the drum in the field out of fear of the police raid. Later in the morning, they took it again, but the pressure cooker bomb remained in the field. They may have thought that the bomb was also in the drum. We think that the bomb’s remote control was left in that drum.”

On Jan 10, the joint forces recovered a bomb kept in a bag on the southern side of Alimuzzaman Bridge in Faridpur city. After deactivating the bomb, police said it was remote-controlled.

A team of police’s counterterrorism unit went to Faridpur on Jan 11 to defuse the bomb. Police inspector Shankar Kumar Ghosh of the team told journalists at the time, "It was a powerful bomb operated by a remote device."

Again, on Wednesday morning, police reported a “weak” explosion at the gates of a court in Barishal. Footage captured on CCTV cameras shows that the explosion suddenly sent dust and smoke flying.

The CCTV footage did not show anyone throwing the bomb. Questions have also been raised about whether it was a remote-controlled bomb.

However, an official of the Barishal city police, on condition of anonymity, said: “It was not a remote-controlled bomb. We did not find any wires, batteries or materials used to make an IED (improvised explosive device) there.

“Basically, the bomb or cracker is made by putting explosives in a glass pickle jar with a tin lid. We think someone could have thrown it, but it is not clear in the CCTV footage. We are trying to collect CCTV footage from other directions.”

However, police concern has grown after the two pressure cooker bombs were found in Savar and Ashulia, and the pipe bomb was found under an umbrella in Motijheel. A CTTC official says that these bombs are the “signature work” of the bomber Mamun. Following his arrest, Mamun had also mentioned making a “suicide vest” in his statement.

Police officials say that remote-controlled bombs have never been used in Bangladesh before. However, it is known that militants have tried to make remote-controlled bombs at various times. Older Harkatul Jihad or JMB bomb makers used “timed devices” in their improvised explosives. They had a kind of “delay circuit”. When the switch of the circuit was pressed and left for a certain time, it ignited the detonator and the bomb exploded. The detonator had a battery as its power source.

Such “timed devices” were used in the 2001 Ramna Batamul bombing and the Aug 17, 2005 serial bombings.

Although remote-controlled bombs were not used, the police had previously reported the detonation of mobile phone-controlled bombs.

Fourteen years ago, on Jul 17, 2012, a female assistant programmer of the Bangladesh Computer Council was injured in a bomb blast. After arresting three people in the incident, the Detective Branch police said that one of the woman’s colleagues, who confessed to the incident, had left a “cellphone bomb” in her bag. The button phone exploded as soon as the other party received a call. 

Mamun's Past and Present

Police say that Mamun gave a confessional statement to the court after being arrested in the Hotel Olio case. However, a Dhaka court acquitted all 11 suspects in the case, including Mamun, during the interim government's tenure. In reviewing the verdict, the judge wrote: "All the suspects are leaders and activists fighting against the former fascist government."

However, in his statement in the Olio case, Mamun said that he had learnt the ins and outs of bomb-making from a retired Navy officer named Mahfuz. Mahfuz was known as Shobuj Pakhi (green bird) in the neo-JMB secret group.

The main bomb makers of the pro-Islamic State 'Neo-JMB' were Mahfuz alias Shobuj Pakhi, Bhasani University student Ibrahim alias Khabbab Al Mishri, and Mamun.

In March 2017, Mahfuz was killed in a police operation in Moulvibazar’s Nasirpur.

Khabbab al-Mishri was an Egyptian national who was also alleged to be Al Qaeda's chief bomb-making chemist.

Ibrahim was given the names Khabbab and Misri because he had a strong grasp of the chemical mixtures needed for bombs. Mahfuz, another of the chief bomb makers, had a sharp understanding of bomb circuitry.

When those two were killed, the neo-JMB took several steps to keep their third bomb expert, Mamun, safe.

Police conducted raids at different places in 2017 to arrest Mamun. Several officers were injured in a militant attack during an operation to arrest Mamun in Jhenaidah’s Moheshpur.

In his statement in the Olio case, Mamun also mentioned making grenades and “suicide vests” along with pressure cooker bombs.

In 2017, they had planned to bomb the Rath Yatra in Dhamrai. Reconnaissance was also carried out. However, in the end, they did not decide to pursue that plan.

In his statement, Mamun said that on Aug 15, 2017, two pressure cooker bombs made by him were detonated at Hotel Olio. The approximate weight of the two bombs was 30kg, he said.

He claimed the two pressure cooker bombs were made in a house in Bhaluka, were put in rice sacks and brought to Dhaka in the box of a bus.

Mamun then handed over the two bombs to Saiful, who died by suicide when he detonated them under the Mohakhali Flyover.

Police now say that the pipe bomb placed on the “Ulto Rath Yatra” procession route under the Motijheel Metro Station in July was also made by Mamun.

The bomb was fitted in an umbrella in such a way that if someone pressed the button of the umbrella, it would explode. The remote control for the bomb has not been found.

Police are conducting a drive to arrest Mamun, said CTTC Additional Commissioner Mohammad Shamsul Haque. He told bdnews24.com on Wednesday, "Investigations are under way on these matters. We will try to bring anyone whose name comes up during the investigation to justice."

When asked about Mamun, he said: "We are still trying to arrest Mamun; there is nothing left to say about that."