Workers frantically piled sandbags and stones and tried to repair leaking levees as surging water threatened two more cities in the southern province of Sindh yesterday.
Pakistani troops have built around 10 miles of defences to protect Shadad Kot and Qambar, but as water continued to pour into the Indus river last night, the authorities were deeply worried that the lines could be breached.
Already, hundreds of thousands of people have been evacuated from Shadad Kot and the surrounding area. Almost a month after the floods began devastating Pakistan's north-west, in the far south water levels are still rising as the floods make their way towards the sea.
The crucial question is whether they can be stopped and diverted before destroying more communities. Spread across a huge swathe of the country, more than six million people have been left homeless.
"It is the last-ditch effort to save the city," Brigadier Khawar Baig, who was overseeing efforts to save Shadad Kot, told the Associated Press. "We are trying to block the water here. If it crosses over, we fear it will go further south and inundate more towns."
Officials told reporters that the eastern side of the city was threatened by water more than 9ft deep. Levees were constantly being repaired with stones and sand-bags, but the authorities were unsure whether they would be able to do enough.
The scale of the flooding that has spread across Pakistan would have challenged the logistical capabilities of any government. But the slow response of the civilian administration headed by President Asif Ali Zardari has continued to anger those who have lost everything.
Yesterday in Punjab province, hundreds of people who fled the rising waters blocked a major road near the town of Kot Adu in demonstration. They complained that they had been camped out nearby for several days without the authorities bringing any emergency supplies.
The constant concern of aid organsiations is the possible spread of waterborne diseases such as cholera. With so many people forced from their homes, emergency shelters, clean water and food is also going to be required for weeks.
A spokesman for the UN's humanitarian organisation suggested millions of people were currently short of food.
Adding to the country's turmoil, more than 36 people were killed yesterday in a series of bomb attacks in the north-west of Pakistan.
In an attack on the outskirts of Peshawar, the leader of an anti-Taliban militia was killed as he passed through a market, while in South Waziristan, a pro-government cleric and more than 20 other people died in a suicide attack on a mosque inside a religious school which also injured 40.