Indian authorities have evacuated hundreds of thousands of people along the country's eastern coast ahead of a cyclone moving through the Bay of Bengal.

Meteorologists say Cyclone Fani could bring "extremely severe" wind and rain when it hits the Indian state of Odisha on Friday.

Officials say Fani could be the worst storm since 1999, when a cyclone killed around 10,000 people and devastated large parts of the state.

India's special relief commissioner told the Press Trust of India news agency that preparations for Fani have included the country's largest evacuation operation. Tourists have been asked to leave the popular beach town of Puri by Thursday night.

More than 800 shelters have been opened and around 100,000 dry food packets are ready to be airdropped.