NEW DELHI -- Tens of thousands of people fled their homes in low-lying areas of southern India and moved to evacuation shelters on Wednesday to escape a cyclone that was barrelling toward the region's coast.

Cyclone Nivar is expected to bring heavy downpours after slamming ashore near Mamallapuram and Karaikal in Tamil Nadu state, the Meteorological Department said.

The storm, with sustained winds of 120 kilometres (75 miles) per hour and gusts of up to 145 kph (90 mph), is likely to damage crops, trees, houses and electrical poles, it said in a statement.

S.N. Pradhan, director of India's National Disaster Response Force, said thousands of emergency personnel have been deployed in coastal regions of Tamil Nadu, Andhra Pradesh and Puducherry states, where the cyclone was expected to hit Wednesday night.

State governments were expecting widespread damage and cancelled flights and trains as a precaution.

In Tamil Nadu's capital, Chennai, authorities said they are closely monitoring the level of reservoirs and lakes to avoid a repeat of floods in 2015, when nearly 430 people died in the state. Flights at Chennai Airport will remain suspended until Thursday morning.

In Puducherry, top official Kiran Bedi appealed to residents to move to higher areas and stay indoors.

"Move to high places wherever you have to. There are relief centres. Please move there," Bedi said in a video message on Twitter.

In May, nearly 100 people died after Cyclone Amphan, the most powerful storm to hit eastern India in more than a decade, ravaged the region and left millions without power.