Hundreds dead in Indian flood disaster

Flood affected people are rescued in a tractor, right as volunteers go for rescue work in a truck, left, at Kainakary in Alappuzha district in India's Kerala state. Photo / AP

The worst floods in a century in the Indian state of Kerala have so far killed over 300 people and forced more than 200,000 into relief camps, officials say, with the toll expected to rise.

As the southwestern coastal state's chief minister sought military reinforcements to boost rescue efforts, a disaster management official said that, since the monsoon season started about three months ago, more than 320 people had died due to flooding and landslides.

As the waters have risen, many people have found it increasingly hard to access food and other basic amenities, or to reach safety.

During the current monsoon, Kerala has been hit with over a third more rain than average, according to India's weather office. The floods are the worst in a century.

In the latest bout that began nine days ago, 164 people have died and some 223,000 moved into more than 1500 relief camps, Vijayan said.

Further heavy rainfall has been forecast for most parts of the state on Saturday, and authorities said they planned to implement controlled releases of water from dams to manage flows and minimise damage.

Rains are expected to subside to "light to moderate" levels on Sunday, India's weather office said.

A witness in a relief helicopter in Chengannur, a town in southern Kerala, saw people stranded on roof tops and waving desperately for help.

"The town looked like an island dotted with houses and cars submerged in muddy flood waters and downed coconut trees," he said.

Two circling navy helicopters dropped food and water in metal baskets and flown out at least four people, including a three-year-old child.

Anil Vasudevan, the head of the Kerala health disaster response wing, said his department had geared up to meet victims' needs.

"We've deployed adequate doctors and staff and provided all essential medicines in the relief camps," he said.

His teams were also making arrangements to minimise the risk of people contracting waterborne diseases once they return home after the floodwaters subside.

The rains have also disrupted transport networks in Kerala, a major destination for domestic and foreign tourists.

Some crops have also been inundated. The state is a major producer of rubber, tea, coffee and spices such as black pepper and cardamom.

Prime Minister Narendra Modi said on Twitter he would travel to Kerala "to take stock of the unfortunate situation".