The figures are based on initial reports, according to Anupam Srivastava, head of the state unit of the National Disaster Response Force (NDRF).
Three NDRF teams are en route from Pune city to Mahad town in Raigaid district where the five-story building collapsed, Srivastava told CNN.
The teams are expected to arrive at the site in the wee hours of Tuesday morning local time (5 p.m. ET) when they “have a better idea of the situation,” he added.
The southwestern state of Kerala has been battered by rain and flooding this season. At least 43 people, including three children, died earlier this month after torrential rains triggered a landslide.
Monsoon rains have caused deadly flooding in the Indian states of Assam and Bihar since May, affecting more than 2.4 million people, inundating large parts of a national park and killing more than 100 wildlife, including a dozen rhinos.
Elsewhere in the region, Nepal has suffered massive landslides and severe flooding, while nearly a third of Bangladesh – and a fifth of its population of 161 million – has been affected by flooding.
CNN’s Emma Reynolds, Helen Regan and Swati Gupta contributed to this report.