SUKKUR, PAKISTAN // Disease outbreaks pose grave new risks to victims of Pakistan's worst floods in decades, aid agencies said on Friday, potentially hindering already complicated relief efforts as desperation grows. The floods, triggered by torrential monsoon downpours, have engulfed Pakistan's Indus river basin, killing more than 1,600 people, forcing two million from their homes and disrupting the lives of about 14 million people, or 8 percent of the population. A health crisis would tax aid agencies already facing huge logistical challenges. The United Nations is increasingly worried about water-borne diseases. There have been 36,000 suspected cases of potentially fatal acute watery diarrhoea reported so far. It says the floods have affected about one-third of Pakistan. "This is a growing concern. Therefore we are responding with all kinds of preventative as well as curative medication... for outbreaks," said Maurizio Giuliano, the U.N. humanitarian operation spokesman told Reuters. Floods have roared down from the northwest to Punjab province to southern Sindh. UN Secretary-General Ban Ki-moon is expected to visit Pakistan over the weekend to discuss the crisis. Pakistan's overwhelmed government has been on the defensive after its perceived lacklustre response to one of the worst catastrophes in the country's history. The military, which has ruled U.S. ally Pakistan for more than half of its history, swung into action. President Asif Ali Zardari has just started what appears to be damage control by visiting flood victims after drawing heavy criticism for leaving for meetings with European leaders as the disaster unfolded, and not cutting his trip short. Zardari said he lobbied for international aid for flood victims on his trip. Despite the state's deepening unpopularity after its handling of the floods, analysts rule out a military grab for power, or the government's downfall. But social unrest is possible. "Children are dying now as we speak because of lack of access to clean drinking water," said Pascal Cuttat, International Committee of the Red Cross Head of Delegation in Islamabad. In Punjab, Pakistan's bread basket, crowds of people pushed and scratched each other competing for relief supplies. The elderly took food from children. A man grabbed sugar from a burst bag that had fallen on the ground and poured it into in his mouth. Villages have been wiped away. Some people only have a patch of land to stand on. All they see is water. Pakistanis are still at the mercy of the elements. Fresh downpours could bring more destruction, and displacement. Residents of the city of Jacobabad in Sindh were taking no chances. "Out of a population of 300,000, about 225,000 people have left to nearby cities and towns in the past few days," city administrator Kazim Jatoi told Reuters. Panic followed warnings a major surge was heading there from a breach in an embankment along the Indus River. The International Monetary Fund has warned of major economic harm and the Finance Ministry said the country would miss this year's 4.5 percent gross domestic product growth target though it was not clear by how much. World Bank President Robert Zoellick said on a visit to Latvia that the floods were likely to have destroyed crops worth around $1 billion. "All of us will have to pitch in to help," he told a news conference. Wheat, cotton and sugar crops have all suffered damage. Agriculture is a mainstay of the economy. "There may be severe shortages too and riots could well break out," said independent economist Meekal Ahmed. He predicted the fiscal deficit would come under strain and amount to about 8 percent of GDP -- twice this year's target. Prices for food still available in markets are soaring. "Where will I get money from? Rob a bank? Carry out an armed robbery?" grumbled flood survivor Mehr Din, 55. Cholera would create another major crisis. Some officials say there are indications that it may have already broken out. "Disasters such as this one, which largely affect the poor and defenceless, tend to be forgotten soon by the wealthy classes, and the downtrodden classes are rarely the ones that lead unrest," said Najam Sethi, editor of Friday Times. * Reuters