Iran's supreme leader has pledged to rebuild the historic city of Bam, devastated by an earthquake on Friday.
The grief in Bam is all-consuming
Ayatollah Ali Khamenei visited the Silk Route city to tell people the Iranian leadership shared their sorrow as the official death toll rose to 25,000.
President Mohammad Khatami also toured Bam saying whatever the authorities did, it would be "too little" given the magnitude of the disaster.
Many foreign rescuers are pulling out amid little hope of finding survivors.
And the focus of the relief effort is shifting to providing shelter, food and heaters to the tens of thousands of survivors, who face long cold nights out in the open, after the most lethal quake in more than a decade.
The final death toll may reach 30,000, according to some officials.
But the Iranian interior ministry said the search would continue as long as there appeared to be any chance of finding anyone alive in the city, 1,000 kilometres (600 miles) south-east of Tehran.
A 12-year-old girl was rescued with a broken leg from the rubble of one house on Monday morning.
"We share your pain, we have lost our own children," Iran's spiritual leader said.
"We will rebuild Bam stronger than before," he said.
WORST QUAKE SINCE 1990
21 June 1990: 40,000 killed in Gilan, Iran
7 December 1988: 25,000 killed in north-west Armenia
28 July 1976: 500,000 killed in Tangshan, China
President Khatami accompanied by a number of ministers went to review the rescue work and the damage.
"The scale of the tragedy is very high," Mr Khatami said.
"Whatever we do, it will still be too little," he said. "Hopefully, as time goes by more aid will arrive."
The BBC's Jim Muir, reporting from Bam, says the visit of the two men is highly significant - it is a measure of concern at the top of the Iranian leadership.
President Khatami is to convene a government meeting in the regional capital on Tuesday, having brought his whole government to the affected area, our correspondent says.
Death of a city
Iranian state radio reports that the bodies of 25,000 people in Bam and surrounding areas have now been buried.
One AFP correspondent counted between 300 and 400 bodies piled up within the space of just 100 metres (yards), some wrapped in white cloth and blankets, others rolled in carpets.
Bodies in one row were those of babies.
Survivors are sleeping on the streets - in cars, next to fires under blankets, in tents.
With fresh aftershocks rattling the city on Monday, few are willing to return to their damaged homes.
Disease is becoming a real threat with such a large population now exposed to the elements.
"We are talking about the risk of a massive outbreak of all kinds of illnesses and diseases," Hamid Marashi, Iran communications officer for the UN's Children's Fund, told AFP news agency.
Bam with its 2,000-year-old historic citadel was a major Iranian tourist attraction. Now much of that heritage has been reduced to rubble and dust.
"I feel I am burying Bam," Jamshid Rashidi, who has been making mass graves since Friday with a digging machine, told Reuters news agency.
Police reinforcements are said to have been deployed to stem looting - sometimes armed men in vans stealing Red Crescent tents and blankets.
Crushed in their sleep
Bam and the surrounding area was home to more than 200,000 people.
Aid agencies say disaster victims need at least:
Shelter: 3.5 square metres
Water: 7 litres/day
Food: 2,100 kilocalories/day
The earthquake struck on Friday before dawn while most people were asleep and had a magnitude of up to 6.7 on the Richter scale.
Bricks used in buildings in Bam are generally made out of baked mud which turns to dust and sand when buildings collapse.
Hence, there were few air pockets in the rubble for survivors to breathe in.
The Bam quake is thought to be the deadliest the world has seen since 1990 when an earthquake, also in Iran, claimed 40,000 lives.