Eight upazilas under Sylhet and Sunamganj districts were inundated while the rivers are flowing above danger levels due to heavy downpour coupled with onrush of water from upstream.
Authorities closed the schools as Sunamganj-Biswambar-Tahirpur road went under water, snapping the road communications of three upazilas.
According to the officials of Sylhet and Sunamganj district administrations, they have taken all measures to face any situation as more than one lakh people have been marooned.
Deputy Commissioner of Sylhet M Kazi Emdadaul Islam said, "Jointapur, Goyainghat and Companyganj upazilas were flooded caused by rainfall and onrush of water. Low-lying areas of others upazilas went under water during the past few days."
Officials concerned and disaster management committees have been asked to intensify their round- the-clock monitoring to deal with any catastrophic situation caused by flood, he said.
Alongside intensifying monitoring, nine permanent and 185 temporary shelter centers have been set up for the flood affected people, Emdadul said.
Adequate relief materials including dry food and cash and TR rice have been kept stock for the flood-hit people in the district.
Officials of Water Development Board said five upazilas were badly affected by flood due to sharp increase of water-levels of Jadukata and Surma rivers. Flood water entered Sunamganj town causing immense suffering to the people.
Nearly 70,000 people of five upazilas in the district -- Doarabazar, Sunamganj Sadar, Tahirpur, Bishmvarpur and Jamalganj - have been stranded by flood water.
Normal life in these upazilas have severely hampered due to flooding.