– The Washington Post

ISLAMABAD, Pakistan – Hundreds of thousands of people fled an ever-expanding flood zone Tuesday as Pakistan’s leaders called for a greater international response to what they say is the worst natural disaster in the country’s history.

With rain continuing to fall and rivers surging, authorities were closely watching several key dams that are at or near capacity. The Sukkur dam in the southern province of Sindh was considered especially vulnerable; any breach could unleash a torrent of water that would wipe out entire towns and villages.

With floodwaters bearing down, people were on the move, traveling by car, donkey and on foot to escape the danger zone. The evacuations included areas of Hyderabad, a city of 1.6 million people.

Although the flooding was concentrated in northwestern Pakistan when it began two weeks ago, it has spread southward in recent days to inundate areas of Sindh and southern portions of Punjab.

Those regions are heavily agricultural, and the destruction of millions of acres of crops could lead to a food shortage, development officials say. The power shortages that plague the country could also worsen after a major natural gas field was submerged in floodwaters Tuesday. As the impact from the flooding spreads to nearly every corner of Pakistan, there is concern here that the disaster could lead to civil unrest.

Fourteen million people have been affected by the flooding, and the Pakistani government has conceded that it does not have the resources to tackle the crisis. Officials say they have been disappointed by the relatively small amount of international aid that has been offered.

“If you look at the scale of the damage and compare that to the pledges we have received, so far there’s a big asymmetry,” said Sakib Sherani, the government’s principal economic adviser. “Several billion dollars will be required just to feed and house the population temporarily. So clearly, the international community needs to step up.”

The United States has pledged up to $40 million, more than any other country, and has flown in six helicopters from neighboring Afghanistan to assist with rescue and relief efforts. But Pakistan has asked for more, seeking dozens of additional choppers to reach stranded victims.

Meanwhile, in China, the death toll from landslides in the northwest more than doubled to 702 on Tuesday, as rescue crews in three Asian countries struggled to reach survivors from flooding that has imperiled millions.

Rescuers digging by hand through mud found a 52-year-old man who had been trapped for more than 50 hours in a leveled apartment building in the remote town of Zhouqu, where more than 1,000 other people were still listed as missing. Rescuers with search dogs discovered the man, Liu Ma Shindan, who was weak but breathing normally.