Dhaka - More than 100 fishermen were feared drowned in the rough waters of the Bay of Bengal with rising tides setting off flash floods that hit the coastal belt of southern Bangladesh, rescuers and local officials said Wednesday.

The high tides caused by a depression in the bay inundated the low-lying areas of seven coastal districts, leaving hundreds of people stranded at flooded fishing villages and rice farms.

At least 25 trawlers with nearly 300 fishermen on board capsized in the giant waves overnight as the sea remained rough, hampering rescue operations carried out by coast guard sailors and civil volunteers.

"Over 200 fishermen have survived the gusty winds by swimming to the seashore or were plucked from the swirling water by local divers," said trawler owner Muhammad Alauddin from the southern Patuakhali district.

Survivors said the trawlers at sea had ignored the warnings of squalls to take advantage of the peak fishing season.

The Meteorology Office in the capital Dhaka said a well-marked low depression over the north-west bay and its adjoining areas moved west north-westwards and intensified into a monsoon depression.

"The depression is lying over southern Bangladesh and the Orissa coast in India," said a Met Office bulletin.

Coastal inundation in the worst-hit Patuakhali district left homes and businesses under 2-metres of sea water forcing tourists to abandon the exclusive beaches, disaster management officials said.

Tidal waves flooded the southern Khulna region washing away shrimp enclosures, thatched dwellings and rice growing on an estimated 10,000 hectares of lush lands.

Barguna, a popular fishing port in the south of the country, was almost deserted because of the evacuation of hundreds of families from the fragile coast to flood shelters.

Islanders on the windswept coast were asked to abandon their seashore homes.

Climate experts say the sudden flooding triggered by rising walls of water wiped out scores of hamlets on the coast.

Operations in the seaports of Chittagong, Mongla and Cox Bazar were disrupted while tidal waves ripped through at least two river dams and disrupted traffic on the strategic Kalapara-Kuakata highway in the south. (dpa)