The Police Bureau of Investigation (PBI) has unraveled the mystery behind the deaths of two employees caused by an air conditioner explosion at the BIAM Foundation building in Dhaka’s Hatirjheel area earlier this year, and arrested two persons, including an admin officer.

The arrestees are BIAM’s administrative officer Zahidul Islam, 38, and his associate Md Ashraful Islam, 36.

The PBI's Special Police Superintendent Abdur Rahman gave this information at a press conference held at the PBI North office in the capital, Kalyanpur, on Monday.

The PBI’s Special Investigation and Operations Unit under the Organized Crime-North Division arrested the two persons on 25 July from separate locations in Kurigram and Dhaka.

According to the case statement, the explosion occurred around 3:20 am on 27 February in room 504 on the 4th floor of the BIAM building. Office assistant Md Abdul Malek died on the spot, while the cooperative society’s driver Md Faruk sustained critical injuries and later died while undergoing treatment in hospital.

Following the incident, retired secretary Md Moshiur Rahman, general secretary of the BCS (Administration) Welfare Multipurpose Cooperative Society, filed a case with Hatirjheel Police Station against unidentified individuals.

On 6 May, the investigation was handed over to the PBI as per directives from the Police Headquarters.

During the investigation, CCTV footage and technological analysis revealed that a masked man entered the 5th floor of the building the night before the incident and turned off the surveillance cameras.

The suspect was identified through technology, and Ashraful Islam was later arrested. During primary interrogation, he confessed to his involvement and identified Zahidul Islam as the mastermind.

PBI stated that Zahidul Islam had planned to destroy important documents of the cooperative society with the help of Malek, driver Faruk, and Ashraful. Ashraful was promised Tk10-12 lakh for his role.

On the day of the incident, Ashraful turned off the CCTV cameras, while Malek and Faruk set fire to documents inside the room, triggering the deadly explosion.

The two arrestees were produced before court on 26 July and gave confessional statements under Section 164 of the Code of Criminal Procedure. PBI confirmed that the investigation is ongoing to determine if others were involved.