"Some two million people have been stranded by floods so far," a senior Bangladeshi official says, adding that at least 10 people have been killed this week.
Rivers in Bangladesh have burst their banks and caused the worst floods in the country's northeast for nearly two decades, with about two million people marooned by rising waters.
Floodwater rushing from India's northeast breached a major embankment on the Barak River, inundating at least 100 villages at Zakiganj in Bangladesh, Mosharraf Hossain, the chief government administrator of the Sylhet region, said on Saturday.
"Some two million people have been stranded by floods so far," he said, adding that at least 10 people have been killed this week.
Floodwater has entered many parts of Sylhet city, the largest in the northeast, where another official said about 50,000 families had been without power for days.
Hossain, the chief administrator, said the flooding was driven by both rains and the onrush of water from across the border in the Indian state of Assam.
But officials said the broken embankment on the border at Zakiganj could only be fixed once the water level dropped.
Scarcity of food, drinking water
Many parts of Bangladesh are prone to flooding, and every extra degree of global warming increases the amount of water in the atmosphere by about seven percent, with inevitable effects on rainfall.
In Zakiganj bus driver Shamim Ahmed, 50, said: "My house is under waist deep water. There is no drinking water, we are harvesting rain water."
"Rain is simultaneously a blessing and a curse for us now."
People were seen fishing on submerged roads and some residents took their cattle to flood shelters.
All the furniture in widow Lalila Begum's home was ruined, she said, but she and her two daughters were staying put, hoping the waters would recede within a day or two.
"My two daughters and I put one bed on another and are living on top of it," she said. "There's scarcity of food. We're sharing one person's food and one meal a day."