Leaders in the south Indian state of Kerala opened near-overflowing dams on Monday, after at least 22 people died when heavy rains lashed the state over the weekend.

Rainfall across the state led to flash floods and landslides in several areas, with the Indian army and navy called out to rescue residents.

Opening dams could reduce the risk of potentially catastrophic overflows like those partly blamed for the state's worst floods in a century in 2018, when at least 400 people were killed and 200,000 displaced. But by releasing water downstream, the move could also worsen the situation in areas already experiencing floods.

Authorities have already opened smaller dams to prevent flooding, while state Power Minister K Krishnankutty said in a statement the Idukki dam, the state's largest, will also be opened if the rains continue.

At least 13 people were killed by a landslide in Kuttikkal village, officials and eyewitnesses said.

"There were four landslides that happened there yesterday, the hill behind me, which brought water and other items downwards," a local resident told Reuters partner ANI on Sunday, standing in front of now-barren hillside.

P.K. Jayasree, the top government official in Kottayam district where the landslide took place, said almost six of the dead were from a single family.

Kerala will receive widespread rain, including isolated heavy rains in many places, for two to three days from October 20, the state government said on Monday.