The police filed an unnatural death case in connection with the casualty due to the explosion at a seven-storey building in the city's Gulistan-Siddik Bazar area on Tuesday.
The officer-in-charge (OC) of Bongshal police station, Mojibur Rahman filed the case on Wednesday night.
"So far 19 bodies have been recovered and the number of injured is 43," she added.
The Director General of Fire Service and Civil Defense (DG), DMP Commissioner along with senior police officers, RAJUK officials, Titas Gas Authority and the BSTI team visited the site after the explosion.
Later in the afternoon, Home Minister Asaduzzaman Khan Kamal visited the spot.
Deputy Commissioner (DC) of DMP Lalbagh Division Zafar Hossain told journalists that, "RAJUK, Fire Service and DMP's CTTC are investigating the reason behind the blast. If they find anything in the investigation that suggests sabotage or an explosion, another case will be filed accordingly."
Earlier, a General Diary (GD) was filed on Tuesday in this regard.