Following heavy rain and onrush of water from the hills, rising water levels of a number of rivers in several districts around the country have left people marooned after damaging protection dams and flooding the areas.
Thousands of people have also been marooned in many areas of the hill districts of Chittagong as they went underwater after incessant downpour and flash-floods.
In Moulvibazar, persistent rain and steady onrush of hill waters have raised the water levels of Monu River in Sharifpur of Kulaura upazila by 175 centimetres above the danger level.
Local journalist and resident of Hajipur area in Kulaura Saiful Alam said: "Due to incessant rain for the last three days, the water levels of Monu and Dholai rivers have increased dangerously since the early hours of Tuesday.
"Locals are trying to stop the water flow by using makeshift dams," said Saiful. "The waters in Monu River near the Monu railway bridge and station in Hazipur union are flowing over the danger level. The dams in Matabpur, Madanagar, Chak Ranchap, Hashimpur, Baroigao, and Mondira are in risky situations."
Since Tuesday afternoon, the dams around Chak Ranchap, Madanagar, and Nischintapur, Chatla Bridge, Chanpur, Amtola BGB camp area, and Datta village of Sharifpur union stand at risk of breaking down.
Local mosques are using loudspeakers to ask aid for the locals, while the locals are trying their best to reinforce the dams.
On the other hand, the water levels of Dholai River in Kamalganj upazila have also increased above danger level, causing floods in localities and croplands.
As a result, parts of the dam in nine places in Dholai River, including Madhabpur of Kamalganj upazila, Islampur in Kamalganj Sadar, and Adampur union, are now at risk of being overflowed.
Water Development Board Inspector Abdul Awal informed: "The waters of Dholai River are flowing 25 centimetres over the danger level. The rate at which rainfall is going on, the waters might increase further."
In Karimpur village of ward no 1 of Kamalganj municipality, waters have entered localities and croplands by shattering the dams. The water level is still on the rise.
Mayor of Kamalganj municipality Md Jewel Ahmed said: "Over 200 people have become trapped inside the village due to Dholai river erosion."
A 100-foot area in the Dholai River dam was eroded due to constant rainfall in Surandpur village of Munshibazar union in Kamalganj upazila. As a result, 250 families in Surandpur village have become trapped inside.
In total, around 500 families have become trapped in Karimpur and Surandpur villages in Kamalganj.
Due to water entering through two eroded parts of the Dholai River dam, the streets of Karimpur and Surandpur have become submerged under 2-3 ft of water.
Kamalganj Upazila Nirbahi Officer (UNO) Md Mahmudul Haque and Mayor of Kamalganj municipality Md Jewel Ahmed have inspected the areas around Surandpur and Karimpur where the dams have been damaged most seriously.
Ranendra Sankar Chakrabarty of Water Development Board in Moulvibazar said: "The dams in three places have eroded due to the overflow of Monu River. The waters are increasing due to flooding, and might increase further.
"Everything is in a risky position," said Ranendra. "The flood water this year is greater than last year's. On Tuesday, water flowed 80 centimetres above the danger level in the Monu River."
He added that without any government allocation, he had personally renovated the dams in Monu and Dholai Rivers by spending more than Tk8 crore in the past.
Meanwhile, in Habiganj, the water levels of Khoai River besides Habiganj town have increased by 170 centimetres on Tuesday due to torrential rain in hills in Tripura province of India.
As a result, the villages around Habiganj town are at risk of flooding.
Alarmed villagers have been keeping a keen eye on the dam in Khoai River so no leakages occur at any place.
Habiganj Water Development Board Executive engineer Tawhidul Islam said: "The waters in Khoai River have been flowing 170 centimetres above the danger level since 9:30am on Wednesday.
"The water level would have decreased if the overflow from Tripura province was dampened," said Tawhidul. "Right at this moment, Habiganj town dwellers are at risk."
Tawhidul informed that to fight the overflow of water, Water Development Board has additional sacks of sand in stock. "We are paying attention so that we can take immediate measures if leakages are found at any place in the dam."
However, he said the water level may decrease by afternoon.
In Feni, parts of the dam in eight places around Muhuri River have broken due to heavy and torrential rain in India, causing streets, croplands, homes, and fisheries to be submerged in Parshuram and Fulgazi upazilas.
Due to waters flowing three centimetres above danger level, the parts of the dam broke in these areas.
Kohinoor Alam, executive engineer of Feni Water Development Board, said: "Two parts of the dam in Chitholia union of Parshuram upazila, and parts of dam in eight places in North Daulatpur of Fulgazi Sadar upazila, Dhanimurar, Bairoya, and Banik para broke down."
He said the work for reinforcing the dams at these places could not proceed due to the heavy water flow.
The Water Development Board is working to find out the number of villages that have submerged under water, said Kohinoor.
Meanwhile, the goods in shops in Fulgazi bazar have been damaged due to water entering the shops, while streets in Parshuram have gone under water as well.
In Rangamati, at least 14 villages in Baghaichhari upazila were submerged due to rain and onrush of hill water for the last three days, rendering 60,000 people marooned, according to UNB.
Torrential rain flooded different villages including Karengatoli, Baghaihat, Bangaltoli, Rupkari, Kadamtoli, Tulaban, Gucchagram, Muslim Block, Imam Para, Master Para, Gunia Para, Sarkar Para, College Para and Old Marishya.
A vast area of cropland went under floodwaters, forcing people to take shelter in nearby schools, colleges and madrasas.
Besides, the water level of Kaptai Lake was flowing over the danger mark, inundating low-lying areas of the upazila, including Longdu, Jurachhari, Barkal, Bilaichhari and Naniarchar.
AKM Mamunur Rashid, deputy commissioner of Rangamati, said several villages were flooded as the water level in the Kachalong River rose following the rain.
Several shelters were opened for the flood-affected people, and around 10 tons of rice was distributed among them, he said.
In Khagrachhari, the flooding situation has not yet returned to normal.
Several hundred houses and businesses were flooded, as water levels in the Chengi and Maini rivers rose on Monday following rain.
Md Rashedul Islam, deputy commissioner in the district, said they had already taken necessary preparations to shelter vulnerable families during any natural calamities.