At least 22 people were declared dead as heavy rains, landslides and floods wrecked through the coastal state of Kerala, India, on Thursday, officials said.

The Idukki and Malappuram districts of the state had the most number of casualties. Around 10 people, five each from families in both districts, were washed away due to the landslide.

There were casualties due to rain-related incidents in Wayanad and Kozhikode districts as well.

According to a report from the Hindustan Times, Wayanad district was completely cut off from the rest of Kerala due to landslides.

Kerala chief minister Pinarayi Vijayan tweeted on Thursday saying the National Disaster Response Force (NDRF) was deployed in Alappuzha, Kozhikode and Ernakulam districts.

Earlier on, he had said that the state had requested aid from the Army, Navy, Coast Guard and NDRF.

The rain water, having entered many low lying residential areas, forced the evacuation of many families. Exact estimates were not available.

Houses in many districts including Palakkad and Idukki were submerged due to flooding from the heavy rains. Roads were breaking down as well, reports said.

Early Thursday, the Kerala State Electricity Board (KSEB) opened one of the shutters of the Cheruthoni dam, one of the largest arch dams in Asia, on the Idukki reservoir as a trial run, due to heavy rains. It is the first time in 26 years that the shutter was opened.

Other shutters of the dam might be opened if required, KSEB officials said.

"The increase in water level downstream due to this limited discharge is estimated to be contained within the river banks," Kerala State Disaster Management Authority (KSDMA) said in a release.

The KSDMA announced a red alert — which is issued when the water breaches the highest flood level — yesterday when the water level at the dam touched 2,399 feet. The Full Reservoir Level (FRL) of the dam is 2,403 feet.

Many civilians watched from a distance as the dam shutter opened.

Flights to and from Kochi were stopped due to heavy rains and flooding. "As a measure of precaution, we are stopping ARRIVAL Operation from 1.10 p.m. [3.40 a.m. EDT] today," a senior official at Cochin International Airport (CIAL) P S Jayan said. An emergency control room was opened at the airport.

Around two hours later, CIAL continued to function. The airport is located close to the Periyar river, which can flood due to water from the dam.

The dam, built in 1975, has been a subject of worry in the state for many years. Fear for the stability of the dam has earlier lead to many disagreements between the Indian states of Kerala and Tamil Nadu, which share the dam’s water.

The heavy rains this year has caused the water levels of the dam to almost its FRL. Beyond that point, the stability of the dam is questionable. If the dam were to completely collapse, it can lead to the mass destruction to a portion of the state, completely wiping districts away from the map.

Last month, 40 people died due to heavy flooding in Alapuzha and Kottayam districts in Kerala.

Skymet Weather tweeted saying heavy rains will continue in Kerala for the next 48 hours.

Over 22 Dead In Landslides, Floods In Kerala, India
Indian rescuers conduct rescue operations after a landslide at Kuttampuzha village in Ernakulam district in the Indian state of Kerala on Aug. 9, 2018. At least 20 people were killed in landslides triggered by heavy rains in southern India, an official said, pushing the nationwide monsoon death toll for this year to over 700. Getty Images/AFP