The eastern Indian city of Kolkata has been devastated by a powerful cyclone, the BBC reports.

Cyclone Amphan made landfall in eastern India and Bangladesh on Wednesday, killing at least 15 people as it lashed coastal areas with ferocious wind and rain.

Many of Kolkata's 14 million people are without electricity and communications have been disrupted.

West Bengal chief minister Mamata Banerjee said the devastation was "a bigger disaster than Covid-19".

Kolkata is the capital of West Bengal state which has seen 3,103 confirmed cases of the infection.

"Area after area has been ruined. I have experienced a war-like situation today," Ms Banerjee was quoted as saying by the Press Trust of India news agency.