Thousands of people are fleeing Pakistan's most populous areas as devastating floods sweep towards the south. The army has been helping to evacuate people from the central Punjab and southern Sindh provinces as monsoon rains are expected to continue.
Floodwaters have already ravaged the northwest, leaving more than 3 million people to cope with destroyed houses and crops, and a lack of food and clean water. At least 1,500 people have been killed in the country's worst flooding in decades.
Officials say at least 20 people were killed Thursday when a bus plunged into a rain-swollen river in Pakistani-controlled Kashmir.
United Nations Secretary-General Ban Ki-moon has dispatched his special envoy, Jean-Maurice Ripert, to Pakistan to join the U.N. team already engaged in flood relief efforts.
Pakistani leaders face growing anger over what residents say is a slow government response. Many have also questioned President Asif Ali Zardari's decision to continue a trip to Europe.
Pakistani Prime Minister Yousuf Raza Gilani said so far 100,000 people have been rescued.
The World Food Program said nearly two million people are in need of food assistance.
In Washington, U.S. Secretary of State Hillary Clinton said Wednesday that Pakistan can count on long-term U.S. support. She outlined U.S. aid that has already been sent and announced a program in which Americans can contribute to the relief effort.
The International Red Cross said that in addition to other damage, flood waters have destroyed much of the health infrastructure in the worst affected areas, leaving people especially vulnerable to waterborne diseases.
The United Nations, Britain and Canada also have committed millions of dollars in aid to Pakistan.
Islamist charities, some with suspected ties to militant groups, also have stepped in to provide aid to flood victims.
Prime Minister Gilani announced Wednesday that Cabinet ministers will donate one month's salary to flood victims.
Some information for this report was provided by AP, AFP and Reuters.