Authorities in India issued a flood alert as water levels surged in rivers and dams and record rains left at least four people dead in the southern Tamil Nadu state.
Storms have lashed parts of the coastal state since Saturday night, forcing the government to close schools and colleges for two days, amid fresh warnings of heavy downpours from Tuesday.
Hundreds of emergency workers were on standby across 14 districts of the state, including the capital Chennai where 6.3 centimetres of rain fell on Sunday — the highest in six years.
At least four people died in rain-related incidents and more than 250 homes were damaged, said state revenue and disaster minister K Ramachandran.
He said more than 150 relief camps had been opened and thousands of people were shifted from low-lying areas.
Videos and pictures posted on social media showed residents wading through water on submerged roads. Many cars sat in floodwaters while uprooted trees disrupted traffic movement across the city.
Authorities opened the sluice gates of three reservoirs in the worst-affected Chennai city to let the surplus water out, prompting residents to flee from low-lying areas.
Tamil Nadu and adjoining Pondicherry, a union territory, have received rainfall amounts that are 43 per cent above normal since the last week of October, with forecasters predicting more storms.
The latest downpour was the worst to hit the state since December 2015, when intense rains caused flooding, killed more than 400 people and displaced about 1.8 million people.
The sudden spell of rain is due to the slow movement of a low pressure patch that formed over south-east Bay of Bengal, moved to the Sri Lankan coast and then on to the Arabian Sea where it strengthened, S Balachandran, the deputy director general of meteorology in Tamil Nadu, told The National.
He said “heavy to very heavy” rains were expected in the state from November 9.
Five people have died in Sri Lanka due to heavy rains, reports say.
Indian Prime Minister Narendra Modi on Sunday called Tamil Nadu Chief Minister M K Stalin and assured him of assistance from the central government.
Hundreds of emergency workers from local and national agencies were on standby to deal with any problems.
Rekha Nambiar, commander of the National Disaster Response Force, said rescuers were sent in advance to vulnerable areas.
“We are expecting the situation to further exacerbate over the next 48 hours,” Ms Nambiar told The National.