Aid flows to Iran in quake's aftermath
Khatami: 'Our people are burning in their sorrows'
Soldiers carry a wounded woman as aid workers from Germany arrive at the airport in Bam, Iran.
Rescuers continue the search for survivors. CNN's Matthew Chance.
The death toll from the earthquake in the ancient Iranian city of Bam likely to rise.
Below is an interactive guide to earthquake magnitude and severity:
BAM, Iran (CNN) -- Rescue workers are searching into the night for survivors in the ancient city of Bam, one day after a devastating earthquake struck southeastern Iran, leaving thousands dead and many more injured.
As international aid began to arrive Saturday, homeless residents of the shattered city built fires and huddled in donated tents and blankets as temperatures fell to near freezing.
Iranian President Mohammad Khatami promised he would make sure the aid gets to those who need it "as soon as possible."
"Our people are burning in their sorrows for what has happened," Khatami said in an address on national television.
The severe quake registered a magnitude of 6.6 with the U.S. Geological Survey. It hit near the ancient city before dawn Friday, killing between 5,000 and 20,000 people. Iranian government officials were differing on the number. The higher toll came from an official with the Interior Ministry.
As many as 30,000 people are believed to have been injured, the ministry said.
So far, about 20 people have been found alive.
About 80 percent of the city's buildings were likely destroyed in the quake, including two hospitals.
The city was left with no power, fuel or water, and people were being given bread to eat. Survivors have been clawing at rubble with their hands trying to find others still alive, and distraught relatives were seen wailing in grief.
Bam, a popular tourist attraction, was the site of 2,000-year-old citadel Arg-e-Bam, which was also destroyed in the quake. It was on the register of the U.N. Educational, Scientific and Cultural Organization and has been a World Heritage site.
At least 21 nations have sent or are sending aid, said Madeline Moulin from the U.N. Office for the Coordination of Human Aid. Dozens of nongovernmental organizations also were helping.
The United Nations wants to be sure the extensive aid efforts are effective.
"These have to coordinated and organized," she said. "This is a major task, considering the situation on the site."
The United States is sending more than 200 personnel and more than 150,000 pounds of medical supplies to provide emergency assistance, White House spokesman Scott McClellan said Saturday.
President Bush issued a statement saying that Americans "stand ready to help the people of Iran."
Turkey, Russia, Spain and Britain are also responding to Iran's call for help.
Turkey plans to send "every possible assistance," including "tents, food, medicine -- whatever is needed," said a spokesman for the Foreign Ministry in Ankara.
More than 120 Russian emergency and medical officials will head to the disaster scene, along with equipment, a Russian emergency official said.
Two Russian planes carrying rescue teams arrived Saturday in Iran to help the victims. (Full story)
An aide to Spain's foreign minister said that nation is prepared to send humanitarian aid of various types.
British Foreign Secretary Jack Straw spoke to Iranian Foreign Minister Kamal Kharrazi and offered the services of two specialized search-and-rescue teams. Kharrazi welcomed the offer, and arrangements are under way through the Department for International Development, Straw said.
With the city's hospitals destroyed, many of the injured were taken to nearby towns and cities.
Helicopters and C-130 transport planes had been moving thousands of people to neighboring provincial centers such as Kerman and even the capital, Tehran, about 610 miles (975 kilometers) away.
Five Iranian Red Crescent Society emergency relief teams from neighboring provinces have also been sent to Bam.
The society has deployed two field hospitals and two helicopters to ferry the severely injured to hospitals as well as provide tents and medical supplies. Local volunteers also are assisting.
"The immediate priority is the search-and-rescue phase -- ensuring that survivors are located, given medical attention and transferred to the hospital," Mostafa Mohaghegh of the Iranian Red Crescent Society said in a statement.
The U.N. disaster management team in Tehran is sending two groups to the affected area "to collect, verify and compile information on the extent and impact of the earthquake."
The U.N. Office for the Coordination of Humanitarian Affairs is dispatching a 10-person team to assist in relief coordination. The office said it has made an initial $90,000 grant and is mobilizing 36-40 tons of relief items. These include blankets, kitchen sets, water distribution and purification units, high-energy biscuits and trauma kits.
CNN's Matthew Chance and journalist Shirzad Bozoghmehr contributed to this article.