More than 60 people have been killed in days of flooding, landslides and thunderstorms that have left many people without food and drinking water and have isolated them by cutting off the internet, according to officials.

The devastation in India’s northeast, one of the worst affected regions, has submerged railway tracks, bridges and roads. In the remote state of Assam, 31 of its 33 districts have been affected by floods, impacting the lives of more than 700,000 people, officials said Saturday. At least 18 people have died in the state because of floods and landslides, according to news reports.

At least 33 people were killed in the neighbouring state of Bihar by lightning strikes and heavy rain in its 16 districts, Nitish Kumar, chief minister, said Friday.

Climate scientists have said that India and Bangladesh are particularly vulnerable to climate change because of their proximity to the warm tropical waters of the Indian Ocean and the Bay of Bengal, which are increasingly experiencing heat waves. The rising sea temperatures have led to “dry conditions” in some parts of the Indian subcontinent and “a significant increase in rainfall” in other areas, according to a study published in January by the Indian Institute of Tropical Meteorology in Pune.

On Sunday, India’s meteorological department warned of “thunderstorms with lightning and very heavy rainfall” in many parts of the country’s remote northeast where the Brahmaputra, one of the world’s largest rivers, has inundated vast areas of agricultural land, villages and towns over the past couple weeks.

The floodwaters of the Brahmaputra and other rivers have arrived with fury in Bangladesh, a low-lying nation of about 170 million people, where extreme rainfall and landslides washed away a sprawling Rohingya refugee camp overnight last year. In 2020, torrential rains submerged at least a quarter of the country.

About 2 million people have been affected in the Sylhet region, in the country’s east, in what officials describe as one of the worst floods in many years.

“We haven’t seen such a widespread flood in Sylhet for around two decades,” S M Shahidul Islam, a chief engineer of the Bangladesh Water Development Board, said Sunday.

“Heavy rainfall and increased flow of floodwater through the Surma River is the main reason for this situation,” said Islam, explaining that dams in the area are unable to hold the floodwaters that have started pouring into cities.

At least 10 people have been killed in the region, most drowning after their boats capsized while they were trying to move to safer areas, officials said Sunday. “We still are working to see if there are more casualties,” said Mosharraf Hossain, the top official in the Sylhet region.