Heavy rains under the influence of cyclonic storm Laila lashed coastal areas of Andhra Pradesh and Tamil Nadu on Wednesday, killing 12 people.
Both states are on alert as the cyclone is all set to hit Andhra Pradesh on Thursday.
The impact of the cyclone is likely to be severe, Met officials warned, saying the storm could surge up to two metres above the regular tide.
Coastal areas of north Tamil Nadu have been experiencing heavy rains since Tuesday night.
West Bengal might also experience heavy rains and winds on Thursday evening because of Laila. Met officials have warned fishermen in all three states against venturing into the sea.
Normal life was thrown out of gear on Wednesday as strong winds lashed Andhra, damaging houses, uprooting trees and snapping power and communication lines.
Ten people died, even as more than 100,000 people were evacuated from low-lying areas of Visakhapatnam, Krishna and West and East Godavari districts.
“We did not want to take a chance as the cyclone may make a landfall even in the night. While some people have moved on their own, we are helping others shift to camps,” said a revenue official in East Godavari district.
After a review of the situation, Andhra Chief Minister K. Rosaiah asked district collectors to use helicopters for rescue and relief operations. Six helicopters have been placed at the disposal of the administration for the purpose.
The chief minister also directed his cabinet colleagues to rush to the coastal districts to oversee relief and rehabilitation work. The state government has alerted the eastern naval command and the army.
Six companies of National Disaster Response Force have also been moved to most vulnerable districts.
Coastal areas of north Tamil Nadu — Chennai, Nagapattinam, Cuddalore, Kancheepuram, Tiruvallur and Cuddalore districts — have also been experiencing heavy rains since Tuesday night.
A fisherman was killed in Ramanathapuram district, while a woman was electrocuted at Velachery in Chennai.
West Bengal is also expected to get heavy rains and winds on Thursday evening.
Authorities have sounded an alert in Kolkata and the districts of East Midnapore, North and South 24 Parganas, Howrah, Hooghly and Nadia.