At least people have died as torrential rains and surging rivers wreaked havoc in northeastern India and neighboring Bangladesh.

The disaster agency confirmed on Thursday that the floods have affected more than 3 million people.

Monsoon rains cause widespread devastation every year, but experts say climate change is altering weather patterns and increasing the number of extreme events.

Eight people have died in the past day in the northeastern Indian state of Assam, disaster officials said, bringing the death toll from downpours since mid-May to 46.

About 2,800 villages in the state have been flooded, affecting more than 1.6 million people, authorities said.

Assam Chief Minister Himanta Biswa Sarma said the current situation in the state is due to rainfall in the upstream Indian state of Arunachal Pradesh.

“No human intervention can stop this,” he said.

In low-lying Bangladesh, downstream from India, floods have affected about 1.8 million people, according to the disaster management agency.

It was warned that water levels would rise over the next three days.

A 21-year-old man died after being swept away by the swirling waters while fishing.

Much of the country consists of deltas, such as the Ganges and Brahmaputra rivers in the Himalayas, which flow slowly towards the sea after flowing through India.

The summer monsoon provides 70-80% of the annual rainfall in South Asia, as well as causing death and destruction through floods and landslides.

Rainfall is difficult to predict and varies widely, but scientists say the monsoon is becoming stronger and more irregular due to climate change.