Massive floods caused by monsoon rains in northeastern India and Bangladesh have killed dozens of people and left millions of homes under water, regional authorities say.
Both countries called in their militaries on June 18 to help with rescue efforts as more flooding and rains are expected over the weekend.
In India's state of Assam, at least nine people were killed and some 2 million saw their homes submerged, the disaster management agency said.
Lightning strikes in parts of neighboring Bangladesh killed at least 15 people in the past two days, authorities said.
Water levels in all major rivers across Bangladesh were rising to dangerous levels, according to the flood forecasting and warning center in Dhaka, the capital.
The government described the flooding in Bangladesh as potentially the country's worst since 2004, exacerbated by the runoff from heavy rain across Indian mountains.
"Much of the country's northeast is underwater and the situation is getting worse as heavy downpour continues," said Mohammad Mosharraf Hossain, chief administrator of Bangladesh's Sylhet region.
Bangladesh and India have experienced increasing extreme weather in recent years.
Environmentalists have warned that climate change could lead to more disasters, especially in low-lying areas of densely populated Bangladesh.