Officials with Bahia's Civil Defense emergency response agency say intense rains overnight Saturday to yesterday in the town of Lajedinho caused the floods, which also destroyed some 70 houses. Around 200 people have taken shelter in schools and a local gym.
Emergency response personnel were searching the flooded buildings for survivors, the missing and other possible victims today.
Brazil's northeast is in the grips of the worst drought in a century, so the sudden downpour was particularly unexpected.
Lajedinho's Mayor Antonio Mario Lima says about 4.7 inches (12 centimeters) of rain fell in a few hours. That's the equivalent of two months of normal rainfall in the region.