The fire was reported in the afternoon in a flour mill in Dongri area, said the official from the Brihanmumbai Municipal Corporation's Disaster Management Cell.
Fire Brigade personnel were rushed to the spot and they doused the blaze immediately, he said.
Four people received minor burn injuries and they were rushed to the nearby state-run J J Hospital for treatment, the official said.
"Our preliminary investigations suggested the fire was caused by a short-circuit. However, the same can be confirmed only after a proper investigation, " added official.
The short circuit was reported at 8.32 pm and electricity was restored within an hour, he said, adding there was no impact on medical services at the hospital.