A series of earthquakes struck western Iran early Friday, killing dozens and flattening entire villages.
At least 66 people were killed and 988 injured, a medical official in Lurestan province told the official IRNA news agency.
The state-run news service put the magnitude of the quake at 6.0, and the U.S. Geological Survey pegged the temblor at 5.7.
The quakes were centered near Boroujerd and Doroud, two industrial cities about 210 miles southwest of Tehran, the official Islamic Republic News Agency reported.
Provincial official Ali Barani said about 200 villages were damaged, some flattened, The Associated Press reported.
U.S. Secretary of State Condoleezza Rice -- speaking during a visit to England -- said the United States was prepared to send humanitarian assistance if it was required.
The quake was sandwiched between two less-intense quakes measuring 4.7 in magnitude. All three quakes hit the region during a nine-hour period, with the first one hitting western Iran Thursday about 7:45 p.m. (1645 GMT)
Barani told IRNA rescue teams had been sent to the region. He said survivors were in urgent need of blankets, tents and food.
Television showed survivors standing next to their destroyed houses in villages north of Doroud. The television also showed dozens of sheep and goats killed by the quake.
Barani said hospitals in Doroud and Boroujerd were full to their capacity.
Officials called on doctors and nurses on leave to get back to work, AP reported. Iranians are celebrating Nowruz, or new year, and most government offices are closed and their staff on holiday.
"We are afraid to get back home. I spent the night with my family and guests in open space last night," Doroud resident Mahmoud Chaharmiri told AP by telephone.
But Chaharmiri said there were no scenes of destruction in Doroud such as those after previous quakes.
In February 2005, a 6.4-magnitude quake rocked the town of Zarand in southern Iran, killing 612 people and injuring more than 1,400.
A magnitude-6.6 quake flattened the historic southeastern city of Bam in the same region in December 2003, killing 26,000 people.
Iran is located on seismic fault lines and is prone to earthquakes. It experiences at least one slight earthquake everyday on average, AP reported.