The storm is India's strongest tropical cyclone to make landfall in 20 years.
Cyclone 'Fani' barrelled through Odisha on Friday, unleashing copious rain and windstorm that gusted up to 175 kmph, killing at least eight people, blowing away thatched houses, and swamping towns and villages, officials said.
The extremely severe cyclonic storm 'Fani' or the 'Hood of Snake' made landfall around 8 am in Puri, with roaring winds flattening huts, enveloping the pilgrim town in sheets of rain, and submerging homes.
Though the 'extremely severe' cyclone unexpectedly weakened into 'very severe' cyclonic storm in a matter of few hours, it left a trail of devastation in large parts of coastal Odisha, with the seaside pilgrim town of Puri being the worst hit.
At least eight people have been reported dead so far, senior officials said, adding information was still awaited from many areas.
While three people, including a teenage boy, were reported killed in Puri district, three perished in Bhubaneswar and nearby areas. Flying debris from a concrete
structure fatally struck a woman in Nayagarh. An elderly woman died of heart attack at a relief shelter in Kendrapara district, official sources said.
Chief Minister Naveen Patnaik, who reviewed the situation, said Puri district, particularly the holy town where the cyclone first hit the land mass, suffered huge damage. "Energy infrastructure has been completely destroyed. Restoration of electricity is a challenging task," he said.
Hundreds of engineers and technicians were working on a war-footing to restore power supply.
Work is on to restore road communication, thrown into disarray with thousands of uprooted trees blocking the way in innumerable places, Patnaik said.
The chief minister said since the cyclone is still passing through Odisha, it will take time to make an assessment of the damage.
The cyclonic system, whose eye is around 28 km wide, moved around 30 kmph, Director of the Meteorological Centre in Bhubaneswar, H R Biswas said soon after Fani made the landfall.
But within the system, the winds reached speeds of up to 175 kilometres per hour that gusted up to 200 kmph, leaving in their wake uprooted trees and thatched structures,
including in the state capital Bhubaneswar.
National Disaster Response Force Deputy Inspector General Randeep Rana said not many casualties were reported so far as precautionary measures were in place.
The chief minister said nearly 12 lakh people were evacuated and shifted to safer locations within 24 hours ahead of the cyclone from about 10,000 villages and 52 urban agglomerations in probably the largest such exercise at the time of a natural calamity in the country.
The evacuees have been accommodated in over 4,000 shelters, including 880 specially designed cyclone centres where free cooked food is being served to them, he said.
After the landfall, the system is passing through Khurda, Cuttack, Jajpur, Bhadrak and Balasore before it would enter West Bengal, Special Relief Commissioner B P
Sethi said, adding that Bhubaneswar was hit by high velocity wind of around 140 kmph.
Telecommunication lines got snapped in several parts of state capital Bhubaneswar and several other areas. Mobile towers were damaged and power supply was disconnected in many places.
Large-scale damage to thatched and old houses was reported from Puri, Khurda and Cuttack districts, he said.
Summer crops, orchards and plantations also suffered huge damage, he said.
National TV channels showed videos claimed to have been shot by residents of Bhubaneswar where a bus was seen bobbing under the impact of the windstorm before flipping on its side.
A police booth was dragged some 200 ft on a highway by furious winds, while a massive crane alongside a multi-storeyed under-construction building collapsed on a row of empty huts, jolted by the howling storm.
The sound and fury: Watch Cyclone Fani's terrifying impact!
Flight operations at Bhubaneswar airport remained suspended on Friday, while Paradip and Gopalpur ports were also closed as a precautionary measures.
Around 220 trains on Howrah-Chennai route have been cancelled keeping in view passengers' safety, an East Coast Railway official said.
As Fani pummelled Odisha, neighbouring West Bengal braced itself for its fury.
The sky was overcast in Kolkata and several other places since Friday morning as rain came in spurts, inundating several parts of the state capital.
Traffic snarls were reported from different places in the city.
WATCH: Nature's fury unleashed as Cyclone Fani arrives
The storm brought down the political temperature, with West Bengal Chief Minister Mamata Banerjee cancelling all her election rallies that were planned over the next 48 hours and getting down to monitoring the situation.
"The eye of the storm is likely to be weakened when it enters West Bengal. The wind speed will be around 100 kmph to 110 kmph," an official of the meteorological department said.
A red alert has been issued in coastal areas and fishermen have been asked not to venture into the sea.
Several districts including East and West Midnapore, North and South 24 Parganas besides, Howrah, Hooghly, Jhargram, Kolkata and the Sundarbans are likely to be hit by the storm that would then move towards Bangladesh and taper off.
No flights will depart or arrive at Kolkata airport from 3 pm on Friday to 8 am Saturday, aviation regulator DGCA said in New Delhi.