The Singapore Civil Defence Force said the fire was located in the centre of the unit situated in Geylang Lorong. The blazes, which began early in the morning, were extinguished within 30 minutes.
The cause of the fire was being investigated.
Three people were pronounced dead at the spot while nine others including two fire-fighters injured in the fire were rushed to a nearby hospital.
The New Paper, a local tabloid, reported that the occupants of the shophouse belonged to India, China, Malaysia and Bangladesh. The identity of the victims was being probed.
The non-government organisation, working to support foreign workers, would also assist the victims and their next of kin besides assisting the injured workers, Bernard Menon, MWC Executive Director said.
He added that the "foremost objective is to find out how they (workers) are and reassure them of our readiness to assist them, should their employer for any reason be unable to do so.
