As many as 20 units of the Fire Service and Civil Defence brought the blaze in the slum at Mirpur Section-7 under control around three and a half hours after it started around 7:15pm on Friday.
A Fire Service official said two people were injured, but could not confirm whether they were burnt.
There has been no report of anyone missing in the fire, Dhaka Metropolitan Police Deputy Commissioner Moshtaque Ahmed told bdnews24.com later at 11:15pm.
One of the residents of the slum, Shahadat Hossain, told bdnews24.com the slum has three units – No. 7, No. 8, and Arambagh, with a total of around 1,000 families.
The fire burnt down his shanty after originating from the centre of the slum, Shahadat said.
Many people have got out and there is an exit through the backside as well, Inspector Rabbani said.
The blaze destroyed everything as most of the shanties were locked from outside, he said.
The floor of the Al-Arabiya mosque houses vegetables, groceries, and clothing shops, and some of these have been gutted, Ove said.
There are a multi-storey building, a BGMEA hospital and several garment factories next to the mosque.
The authorities evacuated the workers and shut down the factories immediately after the fire started, locals said.
Sub-Inspector Mohammad Faruk of police’s Special Branch said they were yet to find out the origin of the fire.
State Minister for Disaster Management and Relief Enamur Rahman and Dhaka City North Mayor Atiqul Islam visited the site and assured the victims of assistance.
They also said the authorities made arrangements so that the slum-dwellers, now rendered homeless by the fire, can stay in five schools in the neighbourhood for now.