A fire at Manzur Khan Plaza in Chawkbazar, Old Dhaka, remained uncontrolled more than five hours after it broke out on Monday afternoon.
Nine units of the Fire Service and Civil Defence were working to bring the blaze under control, officials said.
The fire broke out at a shop on the sixth floor of the seven-storey building at around 5:02pm. Firefighters reached the scene shortly afterwards and began operations.
Narrow lanes, dense smoke and a shortage of water were hampering firefighting efforts, according to Fire Service officials.
The narrow roads were also preventing large firefighting vehicles from reaching the site.
The cause of the fire and the extent of the damage could not immediately be determined. No casualties had been confirmed in the initial reports.