ISLAMABAD - Violent swells have swept away roads, homes, schools and hospitals across much of Pakistan. Millions of people have been driven from their homes, struggling through waist-deep, fetid water to reach islands of safety.

Nearly all of the country's crops along with thousands of livestock and stores of wheat and fertiliser have been damaged - prompting warnings of a looming food crisis.

Since a deluge of monsoon rains lashed Pakistan last week, piling more water on top of more than two months of record flooding that has killed hundreds of people and displaced tens of millions, the Pakistani government and international relief organisations have scrambled to save people and vital infrastructure in what officials have called a climate disaster of epic proportions.

Floodwater now covers around one-third of the country, including its agricultural belt, with more rain predicted in the coming weeks. The damage from the flood will likely be "far greater" than initial estimates of around US$10 billion (S$14 billion), according to the country's planning minister, Mr Ahsan Iqbal.

The flooding has crippled a country that was already reeling from an economic crisis and double digit-inflation that has sent the price of basic goods soaring.

Now the flooding threatens to set Pakistan back years or even decades, officials warned, and to fan the flames of political tensions that have engulfed the country since Prime Minister Imran Khan was ousted this past spring.

The damage to the country's agricultural sector could also be felt across the globe, experts warn.

Pakistan is one of the world's top producers and exporters of cotton and rice - crops that have been devastated by the flood. As much as half of the country's cotton crop has been destroyed, officials said, a blow to global cotton production in a year when cotton prices have soared as other major producers from the United States to China have been hit with extreme weather.

The floodwaters also threaten to derail Pakistan's wheat planting season this fall, raising the possibility of continued food shortfalls and price spikes through next year.

It is an alarming prospect in a country that depends on its wheat production to feed itself at a time when global wheat supplies are precarious.

"We're in a very dire situation," said Ms Rathi Palakrishnan, deputy country director of the World Food Programme in Pakistan. "There's no buffer stocks of wheat. There's no seeds because farmers have lost them.

"If the flood levels don't recede before the planting season in October, we're in big trouble," she added.

Prime Minister Shahbaz Sharif's government, along with the United Nations (UN), has appealed for US$160 million in emergency funding to reach 5.2 million of the country's most vulnerable people.

The scale of the devastation in Pakistan stands out even in a year punctuated by extreme weather, including heat waves across Europe and the United States, intense rain that has drenched parts of Asia and the worst drought to hit East Africa in decades.

Since the start of the monsoon season in Pakistan this summer, more than 1,300 people have died in floods - nearly half of whom were children - and more than 6,000 have been injured, according to the UN.

Around 33 million people have been displaced. Floodwater now covers around (260,000 sq km) - an area larger than the size of Britain - with more floods expected in the coming weeks.

Sindh province, which produces around one-third of the country's food supply, has been among the hardest hit by the rains. The province received nearly six times its 30-year average rainfall this monsoon season, which has damaged around 50 per cent of its crops, according to the U.N.'s Food and Agriculture Organization.

In Sanghar, one of the largest cotton-producing districts in Sindh, Mr Imdad Hingorja, a 45-year-old farmer, owns a small plot of land and was growing cotton. He said that the rains and floods came exactly when the crops in his fields were ready to harvest.

"I have lost everything now. There is (nearly 2m) of water in my fields, and I do not know how long it will take the water to dry," said Mr Hingorja, whose sole source of income to feed his five-member family is farming.

Mr Hingorja recently took a loan from a relative to buy new seeds and fertiliser after his stores washed away in the floods. But if the waist-deep water does not subside by the time he needs to plant, he does not know what he will do.

"Floods are God's wrath, and we cannot escape from it. But who will tell it to the lender who will now ask me to pay back his money?" he said. "I will have not only lost my standing crops but also wasted my entire agriculture year."

In Tank District in Khyber Pakhtunkhwa, a vast province in the north-west, the flooding washed out 35 acres of land that Rahimullah Khan, 47, cultivates, destroying his entire crop of rice, corn and sugar cane. He had poured his yearly savings into the crops, he said, and borrowed around 135,000 Pakistani rupees - or nearly $1,700 - for fertilizer.

"I am left with nothing but a pair of cows," Khan said. "The dairy from the cow is the only thing keeping my children from complete hunger." But if the water recedes, he added, he will have to sell the cows to pay back his loans and gather the resources he needs to plant his fall wheat crop.

Officials have warned that the damage and economic losses will be felt throughout the country for months and years to come. The loss of cotton to Pakistan's textile industry, which contributes nearly 10% of the country's gross domestic product, could hamper any hopes for an economic recovery.

Aid officials have warned that even after the floods subside, rural communities face a possible second wave of deaths from food shortages and diseases transmitted by contaminated water and animals. And severe inflation and shortages of fresh produce will likely hit urban centres unaffected by the flooding.

To address the immediate needs of the millions affected by the flooding, aid groups and the Pakistani government have launched rescue efforts and mounted emergency aid distribution.

"The Pakistani people are facing a monsoon on steroids - the relentless impact of epochal levels of rain and flooding," U.N. Secretary-General Antonio Gutteres said in a message launching an appeal for international assistance to Pakistan.

But the scale of the crisis has complicated relief efforts, Pakistani officials say. And as conditions worsen, anger has risen across Pakistan over the government's response.

"We were left to fend for ourselves," said Mr Mushtaq Jamali, 84, a farmer from Sindh province.

"There was not a single government official or elected representative in our village to help us to evacuate."

NYTIMES