Tens of thousands of people have been evacuated from flood-threatened areas in the south since Saturday. Most of the city of Shahdadkot's 100,000 residents were escorted to safety or were able to get away.
Pakistan's weak civilian government has faced an outpouring of fury over sluggish relief efforts, while officials warn the country faces ruinous economic losses of up to 34 billion euros.
Najam Sethi, editor of the inflential weekly Friday Times in Lahore, told RFI that criticism of the government contrasts with praise for the military.
"Public opinion is building up in favour of some sort of discreet military intervention to create a government … that is more responsive to the needs of the people and more credible in terms of harnessing resources in this type of situation," he said.
"The army’s credibility is running very high," he added, though he said an outright coup was unlikely.
Millions of survivors are in desperate need of food, shelter and clean drinking water, and require humanitarian assistance to survive. Concerns are growing about potential cholera, typhoid and hepatitis outbreaks.
Disaster management officials say that the scale of the flooding is much larger than Pakistan's 2005 earthquake, which killed 73,000 people and made 3.3 million homeless.
Maurizio Giuliano, spokesman for the UN Office for the Coordination of Humanitarian Affairs (Ocha) in Islamabad, told the AFP news agency that 1.5 million people were being treated for everything from respiratory and skin infections to diarrhoea.
"The estimate of those currently without shelter is now 4.8 million. Tents and plastic sheets are in the pipeline for 2.4 million people, while one million already received these items," Giuliano said?
The UN said it has received contributions and pledges totalling 250 million euros for relief activities.
The International Monetary Fund is expected to begin talks with officials this week on restructuring an eight billion dollar loan, which was approved in 2008 to help Pakistan cope with attacks by Islamic radicals, 30-year-high inflation and fast-depleting reserves.