"I could not salvage a single thing. I don't know what will I do," 58-year-old Abdul Hamid, who ran a tea stall inside the slum, told AFP as he broke down in tears.
Authorities eventually got the blaze under control and no-one was killed, although several people had minor injuries, firefighters said. Many residents - largely low-income garment factory workers - were not in the slum as they had left their homes to celebrate the Muslim Eid al-Adha holiday with their families. "Otherwise, the damage would have been bigger," local police chief Golam Rabbani said.