A special bulletin of Bangladesh Meteorological Department on Friday at 6 p. m. local time said the cyclone was now staying at 495 km southwest of Bangladesh's Mongla port in southern Khulna region and 620 km southwest of Chattogram port in southeastern Bangladesh.
Ayesha Khatun, a senior meteorologist, told journalists Friday night that weather forecasters were asked to hoist danger signal No. 6 for Chattogram and Cox's Bazar, a seaside city in southeast Bangladesh and signal No. 7 for Mongla seaport in southwest Bangladesh.
All the fishing boats, trawlers and maritime vessels have been advised to remain in shelter till further notice, reports Xinhua news agency.
TV reports said southern and southeastern coastal districts have been experiencing gusty winds from Friday morning as the cyclone was approaching.
Television footage showed Friday afternoon widespread flooding in coastal areas of Khulna and Chattogram and other districts where hundreds of thousands of people have reportedly been evacuated from their homes.
Announcements were being made in loudspeakers in the coastal districts and red flags were raised in disaster prone areas.
Cities including capital Dhaka are experiencing drizzle and gusty wind on Friday afternoon as an impact of the advancing cyclone.
Tornado and cyclones are common occurrences in Bangladesh.
Cyclone Aila, which hit Bangladesh's southwestern coast in May 2009, left at least 179 people dead and over 3 million affected, with an economic loss of 18.85 billion taka.
In 2007, Cyclone Sidr hit the country's southwestern coastal belt, leaving more than 4,000 people dead or missing.
( With inputs from IANS )