Super cyclone Amphan battered West Bengal and Bangladesh's coastal area and badly damaged parts of the Sundarbans, a UNESCO (United Nations Educational, Scientific and Cultural Organization) world heritage site.
Sundarbans, the largest mangrove forest in the world, spreads across India and Bangladesh and is known for its unique flora and fauna.
West Bengal's principal chief conservator of forests and wildlife Ravi Kant Sinha said the cyclone has already started hitting the forest areas.
"A few of our locations are badly damaged, very high-speed winds and water has entered our locations," Sinha said, reports CNN.
In a tweet, the Indian Met Office said Super Cyclone 'Amphan' crossed West Bengal-Bangladesh coasts as a very severe cyclonic storm with speed of 155-165 kmph gusting to 185 kmph across Sundarbans.
The cyclone has already hit the coastal district of Khulna with strong winds and heavy rainfall. Three deaths were reported from the coastal districts. One of the victims was a Bangladesh Red Crescent volunteer, the organisation said.