Cyclone Amphan has made landfall in eastern India and Bangladesh, killing at least 15 people as it lashed coastal areas with ferocious wind and rain.
Trees were uprooted and homes toppled in both countries, including in the Indian city of Kolkata in West Bengal.
Nearly three million people were evacuated – most of them in Bangladesh – before the severe storm hit.
Coronavirus restrictions have been hampering emergency and relief efforts.
Covid-19 and social-distancing measures have made mass evacuations more difficult for authorities, with shelters unable to be used to full capacity.
The storm is the first super cyclone to form in the Bay of Bengal since 1999. Though its winds have now weakened, it is still classified as a very severe cyclone.
“Our estimate is that some areas 10-15km from the coast could be inundated,” said Mrutyunjay Mohapatra, the head of India’s meteorological department.
Amphan began hitting the Sundarbans, a mangrove area around the India-Bangladesh border home to four million people on Wednesday afternoon, before carving north and north-eastwards towards Kolkata, a historic city that was the capital of the British Raj.
It was moving with winds gusting up to 185km/h (115mph). Amphan is expected to move further into Bangladesh on Thursday, and later Bhutan.
Meteorologists warn there could be up to 300mm more rainfall to come, which could increase the risk of flooding and deadly mudslides.