Authorities in Dhaka on Wednesday night ordered a massive evacuation in the coastlines with the Met office issuing "great danger signal" for southwestern Mongla and danger signal for south-eastern Chittagong and Cox's Bazar ports in view of the severe cyclonic storm created over Bay of Bengal.
The concerned deputy commissioners have been asked to take necessary steps, including evacuation, Disaster Management Ministry's Joint Secretary Mohsina Ferdowsi told PTI.
She said a central control room in Dhaka was in constant touch with local administration in 16 coastal districts and the concerned agencies to monitor the situation while an emergency inter-ministerial meeting was convened for Thursday morning to set strategies for coordinated rescue and relief efforts.
Her comments came as the Met office at 8 pm issued the "danger signals" for the three maritime ports as the severe cyclonic storm 'SIDR' with hurricane strong winds at its core roars over the Bay of Bengal and is moving towards the northern shoreline.
The earlier Met office bulletin issued at 6 pm said the cyclone was packing winds of 165 kmph at its core and was rising to 185 kmph in gusts or squalls. The storm was 755 km south-west of Chittagong, 675 km south-south-west of Cox's Bazar and 705 km south of Mongla ports.
Meteorologists said the cyclone could hit the coastline with full vigor late on Thursday while its "peripheral winds" could brush the coast from Wednesday midnight whipping up surges three to five feet above the "normal astronomical tides".
Red Crescent's Cyclone Preparedness Centre director M Nasirullah said more than 40,000 Red Crescent volunteers were asked to launch the evacuation campaign in the coastline where the number of vulnerable people are nearly 1.20 crore.
The volunteers are using sirens, loudspeakers and whistles asking people to move out of their homes and move towards safety, including cyclone shelters, the state-run BSS reported from coastal Bhola.
Similar reports were received from 13 other coastal districts where the residents and officials said they witnessed gloomy weather featured by drizzles and strong wind while the sea appeared very rough.
Officials in the port city of Chittagong said they already identified the most vulnerable areas in the district, which were experiencing gloomy weather coupled with drizzles and squally winds since Tuesday night.
The reports from the other coastal districts said several hundred fishing boats took shelter in the coastline while the authorities ordered temporary suspension of launch or ferry services in internal routes.
But local officials and fishermen groups said despite the earlier warning signals, several hundred boats were yet to return to the coast since the "sea was not that much rough earlier".
Chittagong, Cox's Bazar and Mongla port authorities asked the vessels at its berths to move away as soon as possible after completion of loading and unloading of cargoes and suspended further sailing of vessels from Tuesday morning.
A Chittagong port official said they also stopped handling work of cargoes at outer anchorage of the Bay of Bengal from Tuesday morning and added that 243 coaster vessels, which were waiting at the port navigation channel were asked to leave for safer places.