Thousands of people are being evacuated from villages along India's eastern coastline ahead of a severe cyclone.
Cyclone Fani is heading towards the state of Orissa with wind speeds in excess of 200 km/h (127 mph), and is expected to make landfall on Friday.
Officials have shut down operations at two major ports on the east coast, and thousands of officials are helping to evacuate people in low-lying areas.
Andhra Pradesh and Tamil Nadu states are also on high alert.
Officials told BBC Hindi that around 800,000 people are in the process of being evacuated. Nearly 100,000 of them will be evacuated from the city of Puri where Fani is predicted to make landfall on Friday morning.
"We are maximising efforts at all levels for evacuation," Bishnupada Sethi, Orissa's Special Relief Commissioner, told Reuters.
Puri is also home to the 858-year-old Jagannath temple and officials fear it could be damaged by the cyclone.
Meanwhile, all schools and universities in the state have shut.
The Indian Navy said it had sent seven warships to the area, and six planes and seven helicopters were on standby for relief operations.
Forecasters have warned that torrential rain could trigger a storm surge of about 1.5m (5ft) in some low-lying areas of Orissa.
Storm clouds gather over the Indian city of Visakhapatnam
Cyclone Fani will be the fourth storm to hit the country's east coast in the last three decades.
In 2017, Cyclone Ockhi killed more than 200 people and displaced hundreds. In October of last year, officials in Orissa evacuated hundreds of thousands of people when another cyclone struck.
Which areas will be affected?
The cyclone is currently moving up the Bay of Bengal, east of Andhra Pradesh.
HR Biswas, director of the meteorological centre in Orissa's state capital, Bhubaneshwar, said at least 11 districts would be hit - and that they have "suggested people stay indoors".
India's National Disaster Management Authority has also warned people along the rest of India's east coast, especially fishermen, not to go out to sea because the conditions are "phenomenal".
The agency said the "total destruction of thatched houses" was possible, as well as "extensive damage" to other structures.
Once the cyclone has made landfall in eastern India, it is expected to move towards Chittagong in Bangladesh in a weaker form on Saturday.
The port city of Cox's Bazar, where hundreds of thousands of Rohingya refugees live in camps with minimal shelter, is also on alert. But the cyclone is currently not expected to hit the refugee campus unless it changes path, which is not very likely.
In February the International Federation of Red Cross and Red Crescent Societies (IFRC) began distributing tarpaulins ahead of the region's "cyclone season" - but warned that if a deadly storm rolls in, shelters made of battered bamboo and shredded plastic would offer little protection.
Indian officials say they have set up more than 850 shelters, which are thought to be able to hold almost one million people.
The navy, the coast guard and the National Disaster Response Force have all been prepared for deployment. It has also stationed two ships with divers and doctors at the southern port cities of Vishakapatnam and Chennai (formerly Madras), an official told local media.
Local media report that about 81 trains travelling to and from coastal cities have been cancelled.