The United States Wrestling Federation has sent a letter of condolence to the Iranian federation Monday, expressing its deep grief on the terrible quake in Bam, southeast of Kerman province, IRNA reported from Tehran.

The US officials expressing their sorrow on the deaths of thousands of people wrote, "We pray for the survivors and bereaved families and know we can never perceive the depth of this huge disaster in your proud country.

"We know the Iranians are brave, strong, and honorable and overcome this regrettable event.

"Let us share our grief with you on this painful disaster. May the Most High bestow your patient people great forbearance for this crunch time."

A killer quake with a magnitude of 6.3 degrees on the Richter scale, the world's most lethal one in at least 10 years, leveled the city and suburban villages before dawn on Friday, 05:28 local hours (0158 GMT), when most people were still sleeping in their mostly mud-brick houses.

Round-the-clock relief efforts were complicated by piles of bodies in the streets, overflowing cemeteries, bitterly cold nights, rain, and aftershocks.

Interior Minister Abdolvahed Mousavi-Lari said some 20,000 bodies had been recovered, but the death toll was likely to be much higher. Aid poured in from around the world to help deal with the huge disaster.