KHULNA, May 20 (CNA) - The strongest cyclone in decades slammed into Bangladesh and eastern India on Wednesday (May 20), sending water surging inland and leaving a trail of destruction as the death toll rose to at least nine.

High winds and torrid rains pounded coastal villages and cities, bringing down power lines, uprooting trees and inundating homes.

"The situation is more worrying than the coronavirus pandemic. We don't know how to handle it," India's West Bengal state leader Mamata Banerjee told reporters late Wednesday.

"Almost everything is destroyed in the coastal villages of the state."

Authorities had scrambled to evacuate more than three million people from low-lying areas, but the task was complicated by the need to prevent the spread of coronavirus.

In Bangladesh officials confirmed six deaths including a five-year-old boy and a 75-year-old man, both hit by falling trees, and a cyclone emergency volunteer who drowned.

Bangladesh meteorological department chief Shamsuddin Ahmed said the cyclone hit the southwestern coastal district of Satkhira with winds at 151 kilometres per hour.

Some three million people were left without power, Bangladesh officials said. Much of the impoverished nation of 168 million people was pounded by heavy rains.

Three other people died after being hit by uprooted trees in India's West Bengal, the state's disaster management minister Javed Khan told AFP.

Two other fatalities were reported by Indian media in Odisha state. AFP could not verify the deaths.

Some 224.6 millimetres of rain fell from early Wednesday and winds up to 113 kph lashed Kolkata, capital of West Bengal state and home to some 14.7 million people.

Some of the historic city was plunged into darkness as power lines were knocked out.

Video shared on social media showed electricity transformers sparking and exploding in the wild weather. Media reports said 5,500 houses were damaged in one West Bengal district.

The cyclone is expected to weaken as it moves north and northeast, and recede to a tropical depression by midday Thursday, the Indian Meteorological Department said.