Pakistan - First responders in southern Pakistan were scrambling to evacuate millions of people from remote villages on Friday as the region nervously awaited the arrival of rainwater flowing from the country's north, officials said.

The rescue efforts in the province of Sindh, which was has been the worst hit province in a series of floods that have occurred since mid-June, were being supported by military helicopters and boats, provincial government spokesperson Murtaza Wahab said.

"It is a race against time," said Wahab, who was overseeing the evacuation.

Pakistan's River Indus, which flows from the Himalayas to the Arabian Sea in the south, has once again burst its banks following heavy rains in the mountains last week.

Environment and Climate UN says Asia hit hardest by climate disasters as China sees massive flooding

Almost 600,000 cubic feet of water per second is now flowing downstream and will shortly reach major cities in Sindh, the disaster management agency said.

The death toll from the climate emergency has already reached 1,208 and was expected to rise, the agency said in an update on Thursday.

"We are trying to reach people who are still in the middle of water without food and shelter," said Rustam Jamali, a rescue worker from the city of Dadu in Sindh province.

UN agencies on Thursday warned that millions of children and pregnant women were at high risk and need urgent humanitarian assistance.

In the north, where several towns still remain inundated a week after the last rains stopped, thousands are still without food and shelter.

"It feels like being refugees in our own villages. We can't go home a few hundred yards away," said Kamal Uddin Khan from the town of Swat.