The toll since the start of monsoon rains in June stands at 959, including deaths from water-borne sickness, snake bites and landslides as well as drowning.
At least 10.5 million people have been displaced or marooned by the floods.
The country’s flood centre said two major Himalayan rivers that empty into the Bay of Bengal through Bangladesh -- the Brahamputra and the Ganges -- had risen alarmingly in tandem.
Fed by heavy seasonal monsoon rains upstream and melting glaciers in the Himalayas, the Brahmaputa, known as the Jamuna in Bangladesh, was now flowing well above danger level, the centre said.
‘It’s a grim scenario. Major rivers have been rising alarmingly. The country is now in the grip of a second spell of flood,’ said Saiful Hossain, head of the centre.
‘And this time it will have devastating impact because the farmers will not have time recover their losses,’ he said.
Muslim-majority Bangladesh, which has a population of 140 million, has sought an initial 150 million dollars in help from donor agencies with 60 million dollars already pledged as immediate food and medical assistance.
Saudi Arabia alone promised 50 million dollars plus a shipment of five planes of food and medicine.
The agriculture ministry estimated that 290 million dollars’ worth of crops had been damaged in the initial flooding. The cost to infrastructure and housing has yet to be determined.