The fire at Square Pharma's Gazipur factory might have started from welding as the factory was undergoing renovation work, said Fire Service acting director (operations) Lieutenant Colonel Rezaul Karim.
He told the media on Tuedsay (24 May) that a committee would be formed to look into the matter.
Firefighters were still working at the factory in Kathalia area of Kaliakair upazila on Tuesday, a day after 19 units brought the fire under control after a seven-and-a-half-hour effort.
It took a long time to put out the fire due to inadequate fire extinguishing system and storage of liquid chemicals at the factory, said Dinmani Sharma, deputy director of the Fire Service.
He said the factory did not have adequate fire fighting systems or equipment.
The existing system was half the requirement as one extinguisher is required for every 550 square feet area at any kind of factory.
The main challenge in extinguishing the fire was the factory's huge size of around 70,000 square feet, said Rezaul Karim.
In addition to the huge space, Rezaul said entrances from all sides of the building were very narrow.
There were steel and glass partitions, which firefighters had to break down to get inside.
Huge materials and chemicals for making saline and tablets were burnt in the fire, Rezaul noted.
He said the fire damaged most of the four-story steel building.
Kaliakair Fire Service Station Officer Saiful Islam said that dumping work was going on at the factory on Tuesday afternoon.