At least 59 people are known to have died in lightning strikes and landslides triggered by severe monsoon storms in India and Bangladesh, the BBC reports.
Millions of people have been stranded while emergency workers have struggled to reach those affected.
Forecasters are warning that the flooding is expected to get worse over the next few days.
Bangladesh government officials have described the recent flooding as the country’s worst since 2004.
Unrelenting rains over the last week have inundated vast swathes of the country’s north-east region, exacerbated by runoff from heavy downpours across mountains in neighbouring India