The worst flooding in Pakistan's history has now affected more than four million people and left at least 1,600 dead, says the UN.
All wells have been contaminated and water-borne diseases are spreading, officials say.
The region is midway through monsoon season and more rain is forecast.
The number of affected districts in Punjab has reached seven, while 350,000 people have been moved from neighbouring Sindh province, most of which is on high alert, the United Nations said.
In Punjab, known as Pakistan's "breadbasket" for its rich agriculture, more than 1,300 villages have been affected and at least 25,000 homes destroyed, said disaster relief officials in the province.
In the worst-affected areas, small villages have been submerged.
In large tracts of Kot Addu and nearby Layyah, water levels were so high only treetops were visible.
The 2010 Pakistan floods began in July 2010 after record heavy monsoon rains. The Khyber Pakhtunkhwa province of Pakistan was worst affected. At least 1,600 people were killed, thousands were rendered homeless, and more than fourteen million people were affected. Estimates from rescue-service-officials suggest the death-toll may reach 3,000 victims. According to a recent estimate of United Nations, the number of people suffering from these massive floods in Pakistan exceeds 13.8 million, which is more than the combined total of the 2004 Indian Ocean tsunami, the 2005 Kashmir earthquake and the 2010 Haiti earthquake.
The floods were caused by monsoon rains, which were forecast to continue into early August and were described as the worst in this area in the last 80 years. The Pakistan Meteorological Department said that 300 mm (12 inches) of rain fell over a 36-hour period and more was expected. So far as many as 500,000 or more people have been displaced from their homes. Manuel Bessler, head of the UN Office for the Coordination of Humanitarian Affairs, stated that 36 districts were involved, and 550,000 people were affected, although later reports increased the number to as high as a million affected.
Officials have warned that the death-toll could rise as many towns and villages are not accessible and communications have been disrupted. In some areas, the water-level was 5.5 m (18 ft) high and residents were seen on roof-tops waiting for aid to arrive. At least 45 bridges and 3,700 houses were swept away in the floods. The Karakoram Highway, which connects Pakistan with China, was closed after a bridge was destroyed. The ongoing devastating floods in Pakistan will have a severe impact on an already vulnerable population.
Mean while United Nations has criticized the world nations for responding slowly, despite the ferocity and magnitude of disaster. As of 9 August, only $45 million have been committed, which is far less than several recent natural disasters combined.
The International Rescue Committee contacted me to circulate this information through my blog to help Pakistani people in distress.
The IRC has been providing lifesaving aid in Pakistan for 30 years. they are already working in the areas hit hardest by the floods, including Charsadda, Kohat, Lower Dir, Nowshera, Tank, Mardan and Swat. Last year, many of these same areas were affected by fighting between militants and government forces that uprooted millions of people.
The IRC will also focus on providing clean water, sanitation, shelter and essential supplies to those who have fled the rising waters. With their robust network of local staff and partners already on the ground -- and decades of experience responding to emergencies in Pakistan -- the IRC is well-positioned to help families in dire need.