New Delhi (CNN) Dozens of people have been killed, and tens of thousands more evacuated, after "unprecedented" flash flooding in a tourist hotspot in southern India.

At least 37 people have died since heavy monsoonal rains first struck the state of Kerala on Wednesday, the state's relief commissioner P.H. Kurian told CNN on Sunday.

The area, located on the tropical Malabar Coast, is famed for its network of idyllic waterways

Another 40,000 people living in low-lying areas have now been evacuated to 350 relief camps, as the downpour caused landslides and overflowed reservoirs.

The Shiva Temple in Kochi, Kerala state, is partially submerged on August 9.

Monsoon rains are to be expected in India this time of the year. But after days of abnormally heavy rains, authorities on Friday opened the shutters of water reservoirs in an effort to prevent potentially disastrous breaches.

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