A torrent of water released from an Indian dam has submerged towns and villages in northeastern Pakistan.
Floodwaters now cover hundreds of hectares in Punjab province and river levels are still rising.
Officials say saving lives is the priority and they hope water levels will recede in the next 48 hours.
But it is the monsoon season and heavy rainfall is expected in northern India in the coming days – which means more water will flow downstream.
Monsoon rains bring floods and destruction almost every year. But heightened tensions between nuclear-armed Pakistan and India have weaponised even the stoppage and release of water.
Al Jazeera’s Osama Bin Javaid reports from the Jhelum River.