Cyclone Phailin has struck the coast of India after sweeping across the Bay of Bengal, bringing some gusts of wind of over 300 kilometres an hour.
The sea is expected to rise by three or four metres, with predictions that the storm will be the worst the region has seen in over a decade.
Mass evacuations have taken place in the states of Orissa and Andhra Pradesh.
Half a million people have been moved from their homes to be housed in schools or other public buildings transformed into temporary shelters.
“There are not enough rooms in the shelter and it is tough to find accommodation. We haven’t had a proper meal since last night. We are very troubled due to the heavy rains. The toilets at the shelter are also not functioning,” said one local mresident.
Torrential rain has already caused damage across the poor areas of eastern India. At least three deaths have been reported.
People there are still traumatised by a devastating cyclone in 1999, that left several thousand dead – buried in mudslides, struck by fallen trees or swept away by floods.
The airport at Bhubaneswar, Orissa’s state capital, was closed. Earlier strong winds had made landing difficult.
Many flights were cancelled, leaving passengers stranded.