Officials say that at least three people have been killed and around 160 injured after a cyclone barrelled into eastern India today, damaging houses in the tourist town of Puri.
One million people had been moved into storm shelters.
Trees were uprooted and power and telecom lines snapped as Tropical Cyclone Fani, the strongest storm to hit India in five years, swept ashore in the eastern state of Odisha.
Bangladesh, which lies further up the path of the system, ordered the evacuation of 2.1 million people before the storm arrives tomorrow.
Indian government spokesman Sitanshu Kar said there were no reports of deaths but 160 people were believed injured.
Bangladesh's junior disaster minister Enamur Rahman said 56,000 volunteers were racing to move millions out of the storm's path.
Fani spent days building up power in the northern reaches of the Bay of Bengal before it struck the coast of Odisha this morning, the state-run India Meteorological Department (IMD) said.
Howling winds gusting up to 200km/h (124mp/h) uprooted trees, and driving rain affected visibility, while streets were deserted in the state capital Bhubaneswar and Puri.
"Damage in Puri is extensive, power supply, telephone lines disrupted," Odisha's Special Relief Commissioner Bishnupada Sethi said, referring to the seaside Hindu temple town that is popular with pilgrims and was directly in the storm's path.
Cyclone tracker Tropical Storm Risk put Fani as a powerful category four storm on a scale of one to five. The IMD said the storm was now weakening.
Close to 60km inland, winds brought down electricity poles in Bhubaneswar, where authorities had ordered the airport to stay closed. Schools and colleges in Odisha were also shut.
A major hospital in the city suffered extensive structural damage but all patients and staff were safe, authorities said.
"It was a massive cyclone, like many others our house is flooded. Boundary walls of houses around us have collapsed, trees have been uprooted. It is a panic situation," Anuradha Mohanty, a Bhubaneswar resident, said.
People packed into shelters, spreading mats to wait out the storm, television and social media showed.
More than 600 pregnant women were shifted into safe locations, with nearly 500 ambulances on standby. Some 242 medical institutions had been provided with power back-up, government authorities said.
Heavy rains lashed the Bangladeshi capital Dhaka and a few coastal districts of the country. Seaports have been ordered shut, a government official said.
The storm is not expected to touch the country's southeastern district of Cox’s Bazar where nearly a million Rohingya Muslims are sheltered.
Plants of Indian Oil Corporation Ltd, the country’s top refiner, and power producer NTPC Ltd are operating normally in Odisha.
India's cyclone season can last from April to December, when severe storms batter coastal cities and cause widespread deaths and damage to crops and property in both India and neighbouring Bangladesh.
But recent technological advances have helped meteorologists predict weather patterns more accurately and prepare.
In 2017, Cyclone Ockhi left nearly 250 people dead and more than 600 missing in Tamil Nadu and Kerala.
A super-cyclone battered the coast of Odisha for 30 hours in 1999, killing 10,000 people. In 2013, a mass evacuation of nearly a million people likely saved thousands of lives.
Cyclones typically quickly lose power as they move inland.