Flooding has covered 41 square kilometers (15.8 square miles), about 8 percent of the city's total area, the BNPB, Indonesia's federal disaster management board, said Friday.
About 18,000 people have been displaced from their homes and have complained about a lack of blankets and clean drinking water, the Jakarta Globe reported Friday.
BNPB spokesman Sutopo Purwo said the figures were lower than those from a 2007 flood that killed 80 people "but the current data is only (for three days). It may continue to flood until February."
Tjandra Yoga Aditama, the Health Ministry's director general for disease control, warned flood victims may be vulnerable to dengue fever and leptospirosis. Aditama said makeshift hospitals had been erected in four flood-affected areas.
Weather officials warned Thursday the worst was not over, and Army special forces and firefighters have been called in to rescue the stranded, The Singapore Straits Times reported Friday.