Millions of children and pregnant women are at risk in Pakistan’s flood-hit regions and need urgent humanitarian assistance, the United Nation’s International Children Emergency Fund (UNICEF) said Wednesday.

Children face waterborne diseases and malnutrition due to flooding in the South Asian nation, UNICEF said in a report.

The flooding from the highest rainfall in over three decades has killed 1,200 people since mid-June and affected more than 33 million, mostly in the impoverished south and southwest of the country.

Nearly 600,000 pregnant women in flood-hit regions are in dire need of medical care and mental health services, the United Nations Population Fund (UNFPA) said.

"Up to 73,000 women expected to deliver next month will need skilled birth attendants, newborn care, and support," a report by the agency said.

Millions of women and girls also face the risk of gender-based violence, UNPF said, highlighting threats in regions where families are living in makeshift tent shelters with no access to toilets and proper sanitation.

Children are particularly prone to water-borne diseases like diarrhea, respiratory infection and skin diseases, UNICEF said.

Southern Pakistan braced for more flooding on Thursday as a surge of water flowed down the Indus river, compounding the devastation in a country a third of which is already inundated by a disaster blamed on climate change.

Record monsoon rains and melting glaciers in northern mountains have triggered floods that have killed at least 1,191 people, including 399 children.

The United Nations has appealed for $160 million to help with what it has called an "unprecedented climate catastrophe."

Pakistan has received nearly 190% more rain than the 30-year average in the quarter from June to August, totaling 390.7mm (15.38 inches).

Sindh, with a population of 50 million, has been hit the hardest, getting 466% more rain than the 30-year average.

Some parts of the province look like an inland sea with only occasional patches of trees or raised roads breaking the surface of the murky flood waters.

Hundreds of families have taken refuge on roads, the only dry land in sight for many of them.

The floods have swept away homes, businesses, infrastructure and roads. Standing and stored crops have been destroyed and some 2 million acres (809,371 hectares) of farmland inundated.

The National Disaster Management Authority said some 480,030 people have been displaced and are being looked after in camps but even those not forced from their homes face peril.

The World Health Organization (WHO) said that more than 6.4 million people were in dire need of humanitarian aid.

Aid has started to arrive on planes loaded with food, tents and medicines, mostly from China, Türkiye and the United Arab Emirates.

Aid agencies have asked the government to allow food imports from neighboring India across a largely closed border that has for decades been a front line of confrontation between the nuclear-armed rivals.

The government has not indicated it is willing to open the border to Indian food imports.