Fifteen people were reportedly killed by lightning strikes in Bangladesh, while four died in landslides. At least nine people have been killed in India's Assam state.
Both countries have called out their armies to help distribute food aid and rescue stranded people, with soldiers using "speedboats and inflatable rafts to navigate through submerged areas," according to AP.
Rain is expected to continue through Sunday, at least, exacerbating what one Bangladeshi government expert described as the region's worst flooding since 2004.
Bangladesh, a low-lying country with more than 130 rivers, is highly vulnerable to flooding. The United Nations Intergovernmental Panel on Climate Change has warned that, due to climate change, some 27 million Bangladeshis may have to be relocated over the next decade.