The toll Cyclone Phailin has taken on India's east coast was not immediately clear early Sunday after the storm knocked down power and communication lines in the coastal districts.
Cyclone Phailin came ashore late Saturday in Orissa state, near the border of Andhra Pradesh state, with winds of over 200 kilometers-per-hour.
Weather forecasters predict the storm's winds will continue to be severe through Sunday morning.
Officials blamed the storm's winds for at least three deaths before it moved ashore. The high winds have also uprooted trees, damaged coastal homes and destroyed crops.
In a Saturday briefing, Disaster Management Commissioner T. Radha said huts and older buildings in the storm's path could not withstand its winds. He also said low-lying areas would likely be submerged.
Indian authorities evacuated nearly a half-million people as they prepared for the cyclone, forecast to be one of the country's most powerful storms on record.
On Friday, the United Nations and European Union's Global Disaster Alert System warned that 6.5 million people are likely to face torrential rains and damaging winds.
Cyclones in the Bay of Bengal are common this time of year, frequently wreaking havoc and causing mass deaths in coastal India and Bangladesh. A cyclone hit Orissa state in 1999, killing at least 10,000 people.
Some weather predictors have likened Phailin's size and intensity to Hurricane Katrina, which tore through the U.S. Gulf Coast and New Orleans in 2005, killing more than 1,000 people.