At least 40 people have died in flash floods inundating India’s northeast, officials said Friday, as army teams plotted helicopter rescues for more of the thousands stranded in the deluge.

Violent torrents stuck the remote state of Sikkim on Wednesday after the sudden bursting of a high-altitude glacial lake near India’s borders with Nepal and China.

Climate scientists warn that similar disasters will become an increasing danger across the Himalayas as global temperatures rise and ice melts.

Downstream search-and-rescue teams recovered more bodies overnight as the waters cut a swathe through the countryside towards the Bay of Bengal.

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“Nineteen bodies have been recovered” in Sikkim state, V.B. Pathak, its top civil servant, told AFP.

Shama Parveen, a district magistrate in neighbouring West Bengal, said that an additional 21 bodies had been recovered in her state over the past three days.

Read More: Himalayan lake flooding in India kills 18, nearly 100 missing

Nearly 8,000 others were taking shelter at makeshift relief camps set up at schools, government offices and guesthouses, according to a state government bulletin.

“There may be a window of opportunity for evacuation of stranded tourists by helicopters” with weather conditions improving on Friday, the statement added..