A deadly explosion at a commercial building in Dhaka's Science Lab left three people dead and at least 13  injured on Sunday morning.

The deceased are -- Shafikuzzaman, Abdul Mannan and Tushar, confirmed Dhanmondi police station OC Ikram Ali. Fire service officials are suspecting that the blast originated from an AC unit.

Total five of the injured -- Syed Akbar, 52, Ashrafuzzaman, 36, Asha, 25, Jahur Ali, 52, Hafizur Rahman, 45 -- have sustained burns.

The tragic incident took place at around 10:52am this morning leaving part of the three-storey building partially collapsed. Four units of firefighters were able to douse the fire by 11.15am.

Meanwhile, a team of the Bomb Disposal unit of the Counter Terrorism Investigation Division of Dhaka Metropolitan Police (DMP) is currently working at the scene to analyse the source of the blast, Md Shahidullah, deputy commissioner of Ramna division, told media.

Speaking with The Business Standard Inspector Zillur, in charge of the Special Branch (SB) of Bangladesh Police, (New Market zone), said," If not from an AC unit, the blast could have occurred from a gas cylinder."

Meanwhile, the traffic movement on Mirpur road -- from Science Lab to Nilkhet intersection -- has reopened after being suspended for hours following the explosion. After the explosion, a plume of black smoke was seen billowing from the building.