Heavy rains and winds have been reported in eastern India and Bangladesh, with a super cyclone expected to make landfall in hours.
Both countries have evacuated millions of people in preparation for Cyclone Amphan, which is approaching from the Bay of Bengal.
India’s met department tweeted that Amphan was on course to make landfall “between afternoon and evening”.
The coronavirus outbreak is making it harder for officials in both countries.
India and Bangladesh have asked for schools and other buildings to be turned into temporary shelters – but they need more than usual, in order to house people while maintaining social distancing.
Police in India’s West Bengal state, which is expected to be badly affected by the storm, told the BBC that people were unwilling to go to the shelters because they were afraid of contracting Covid-19.
More than 20 relief teams have already been deployed, and several more are on standby, Indian officials say.
Amphan is one of the biggest storms in a decade, meteorologists warn. It is expected to hit the coast with winds gusting up to 185km/h (115mph) – the equivalent of a category five hurricane.
Officials in Bangladesh fear it will be the most powerful storm since Cyclone Sidr killed about 3,500 people in 2007. Most died as a result of sea water surging in.