More than one million people have packed relief camps to escape devastating monsoon floods that have killed more than 410 people in India's southwestern state of Kerala, officials said on Tuesday.

About 50,000 homes have been destroyed, according to one Kerala legislator, and people are flocking to the camps as the scale of the desolation is revealed by receding waters.

A total of 1,028,000 people were now recorded in about 3,200 relief camps across the state, a state government spokesman told AFP.

Six more bodies were found on Monday, he added, taking the toll to more than 410 since the monsoon started in June.

At Chengannur, one of the worst-hit towns, more than 60 centimetres of water still blocked many roads as more rain fell on Tuesday.

Army teams said several thousand people in the town remained in homes inundated by 10 days of torrential downpours that have battered the state.

Rescue teams in Chengannur on Tuesday finally reached the house of retired army officer KG Pillai, who said up to 2.4 metres of water had engulfed the house where his family had lived since 1952.

“In the past there has never been more than one foot of floods and people are not used to this,” he said.

Many roads and homes around Pillai's house remained inaccessible.

“Around 26 people moved into the first floor of our home” to take refuge from the floods, he said.

A senior army officer involved in the rescue operation in Chengannur said authorities believed most of the people left in town did not want to be evacuated and were instead seeking food and water.

“We received a distress call late yesterday to rescue a disabled child and will be going in today on boats to check if there are others who need assistance,” he said.

Relief efforts

Thousands of army, navy and air force personnel have fanned out across the state to help those stranded in remote and hilly areas.

Dozens of helicopters and even drones have been dropping food, medicine and water to cut-off villages.

Tens of thousands of people in Chengannur and surrounding towns and villages are relying on community kitchens for meals after water from hilly districts in Kerala's north poured down into lowland regions.

“People have lost all or most of their belongings in the last few days,” the officer said.

Shashi Tharoor, a deputy from Kerala and former United Nations (UN) official, estimated that 50,000 houses had been destroyed. He said he would seek possible UN assistance in relief efforts during a trip to Geneva this week.

Millions of dollars in donations have poured into the state from the rest of India and abroad since the extent of the devastation became known.

Supreme Court judges have donated $360 each while the British-based Sikh group Khalsa Aid International has set up its own relief camp in Kochi, Kerala's main city, to provide 3,000 meals a day.