KATHMANDU, Nepal — The death toll mounted Monday from flooding and landslides caused by torrential weekend rains in India and Nepal, as rescuers carried out desperate searches for survivors and officials in nearby Bangladesh braced for the floodwaters to move downstream.

The hardest-hit country appeared to be Nepal, where the police said on Monday that 67 people had died as a result of the monsoonal rains that began on Thursday night and set off widespread flooding, particularly in the country’s southern plains along the Indian border.

Officials said that at least 68 others had been injured in landslides and flooding and that an additional 30 people were still missing. Photos published by Nepal’s news media showed flood victims wading through murky, thigh-high waters, and teams of rescuers plying streets in inflatable boats.