BAM, Iran (AP) _ Rescue teams from around the world joined Iranians in the rush to save anybody still alive Sunday, two days after an earthquake reduced most of this city to rubble and killed tens of thousands of people.

Two U.S. planes carrying food and aid landed in the provincial capital of Kerman early Sunday, said the spokesman for the governor's office, Saeed Iranmanesh.

The scale of the devastation in the Friday morning quake made it difficult to give an accurate death toll, but the Interior Ministry has estimated 20,000 deaths and officials working in Bam have said it could rise to 40,000.

``More than 10,000 bodies have been pulled out of the rubble,'' Brig. Gen. Hasan Rastegarpanah of the Revolutionary Guards said Sunday. The elite guards are the largest single organization taking part in the relief operation.

The city of 80,000 people in southeastern Iran was asleep when the magnitude-6.6 earthquake struck. Experts say people buried in the rubble with access to air can normally survive up to 72 hours, but there have been cases of people living longer.

Help from around the world poured in Sunday. The Associated Press saw rescue teams from Austria, Azerbaijan, Britain, Finland, Germany, Russia and Turkey going over the remains of flattened homes. Several teams had sniffer dogs.

The American planes that arrived Sunday were the first to land in Iran in more than a decade. The United States said Saturday it would send 75 tons of medical supplies and about 200 rescue and medical experts.

The United States has no diplomatic relations with Iran and last year President Bush said the country was part of an ``axis of evil'' with prewar Iraq and North Korea.

``We greatly welcome any assistance from the United States,'' said Keraman governor Akbar Alavi said Saturday.

The inhabitants of Bam complained of a shortage of a drinking water on Sunday. Relief workers were handing out bottled water, but there was not enough.

However, almost all the thousands of homeless did manage to sleep in tents Saturday night, unlike Friday night when most had only blankets between themselves and the sky in temperatures close to freezing.

The Interior Ministry estimated the number of injured at 30,000.

Bam, in southeast Iran about 630 miles from Tehran, suffered such extreme damage because most of the buildings are made of unreinforced mud brick and the quake was centered only about 10 miles outside the city, said Harley Benz, a USGS seismologist.

``The communities in this part of Iran are really not resilient to earthquakes,'' said Benz, head of the National Earthquake Information Center in Golden, Colo. Aftershocks registered as high as 5.3.

Searchers carried the injured in their arms, on stretchers and in the backs of trucks, seeking help outside Bam's ruined hospitals or at the airport while awaiting evacuation to Kerman, the provincial capital about 120 miles away, or other cities.

About 150 people, including an infant, were pulled alive from the rubble, Revolutionary Guards officer Masoud Amiri said. The baby was buried more than 24 hours but was listed in stable condition at a hospital, he said.

Iran opened its airspace to all planes carrying emergency supplies and waived visa requirements for foreign relief personnel.

``The disaster is far too huge for us to meet all of our needs,'' President Mohammad Khatami said.

The leader of an Iranian relief team, Ahmad Najafi, said he feared the toll could reach 40,000. On one street alone, 200 bodies were extracted from the rubble in a single hour on Saturday, he said.

In another part of Bam on Saturday, a gray-bearded man in his 50s, wearing the white turban common to rural villages in this southeastern corner of Iran, watched with resignation as four men dug with their bare hands and a single shovel.

What once was his home was a flattened pile of rubble and dust. He pointed to where the bedrooms should have been, seemingly resigned that none of his three teenage children or his wife would be found alive.

He fainted as he spotted a slender hand protruding from a red pajama sleeve in the debris.

Behind him, the body of a girl in her teens was excavated and quickly covered with a blanket. Then the bodies of his sons and a woman in her 40s were found.

No one was alive.

In another neighborhood, a man interrupted Interior Minister Abdolvahed Mousavi Lari as he spoke to reporters Saturday.

``My father is under the rubble,'' the man said, tears rolling down his face. ``I've been asking for help since yesterday, but nobody has come to help me. Please help me. I want my father alive.''

Lari tried to calm the man and asked an aide to help him.

``There is not a standing building in the city. Bam has turned into a wasteland,'' the minister said.

The earthquake collapsed the walls of the local prison, allowing all 800 inmates to escape, guard Vahid Masoumpour said.

The quake destroyed most of Bam's citadel _ a medieval fortress that is the city's best-known structure. The tallest section, including a distinctive square tower, crumbled like a sand castle.

The U.N. cultural agency, UNESCO, considered declaring the citadel a protected World Heritage Site.

Iran has a history of devastating earthquakes, including one of magnitude 7.3 that killed about 50,000 people in northwest Iran in 1990.