Cyclone Fani, which is forming in the Bay of Bengal, is expected to make a landfall in Bangladesh on Friday.
Khulna and adjacent district will experience severe storm with a wind speed of up to 150-180 km per hour.
The weather department has issued a level 7 danger warning across the coastal lines of Patuakhali, Bhola, Borguna, Barishal, Pirojpur Jhalakathi, Bagerhat, Khulna and Satkhira. The signal at Mongla and Payra ports have also been increased to danger level 7.
Chattogram, Noakhali, Laxmipur, Feni, Chandpur and the port of Cox’s Bazar has been ordered to hoist Danger signal level 6.
The storm was churning up the Bay of Bengal about 320 km (198 miles) south-southwest of India’s Hindu temple town of Puri where special trains were put on to evacuate tourists and the beaches were empty.
India has evacuated more than 300,000 people along its northeast coastline by boat, bus and train, with many villagers piling household possessions on to trucks before fleeing their homes.
Odisha state government has deployed hundreds of disaster management personnel, closed schools and colleges and asked doctors and other health officials not to go on leave until May 15.
(With inputs from Reuters)