|Search ON THIS DAY by date|
The quake centred on the town of Ghir, where almost 1,000 people were feared dead.
The nearby city of Jahrom was also hit, and the tremors were also felt in the ancient city of Shiraz, 100 miles (160 km) away.
Ghir, a busy farming town of about 7,000 people, is reported to have been destroyed, along with up to 60 of the surrounding villages.
General Mohammad Fazelli, in charge of rescue and relief operations, said it was feared there are many more people buried under the debris.
When asked how many, he remarked, "God knows."
The governor-general of the area, Manucher Pirouz, said, "The earthquake was so devastating and has levelled so many homes in as many as 30 villages that it will take days to find out the death toll."
Mr Pirouz flew to the area by helicopter shortly after the first earthquake, and spoke of the damage he had seen during a two-hour flight over the epicentre.
"There was not a single dwelling above the ground," he said. He described survivors staggering among the ruins. "One cried out for his children, another for his father, another for her mother," he said.
The quake hit early this morning, when many of those living in the remote, rural area were already on their way out to the fields.
It's thought most of those who died were the women and children left behind at home and buried under the ruins of their houses.
Smaller tremors have continued to shake the region for most of the day, causing panic among survivors.
Most of those not killed by the quake are camping out on the open plains, staying near their villages to help with the rescue effort.
Planes have been flying into the stricken area all day dropping food, blankets and medical supplies to survivors. Doctors and medical supplies are also being flown in.
Tehran University measured the initial shock at 7.1 on the Richter scale, making it one of the strongest in Iran's history.
It comes four years after Iran's worst earthquake of recent years, when about 20,000 died in the northern province of Khorassan.
The death toll in the Ghir earthquake was eventually put at more than 5,300.
Soldiers, police and villagers continued to pull survivors from the rubble for almost four days after the disaster.
The Shah of Iran rejected offers of international help, saying it could manage the crisis with its own resources.
However, there was evidence of widespread hunger and a lack of shelter and basic supplies, such as shrouds to cover the dead, in the days following the earthquake.
In 1990, Iran recorded its worst-ever disaster, when 35,000 people died and 100,000 were injured in a quake in the Caspian regions of Gilan and Zanjan.
In December 2003, an earthquake measuring 6.7 on the Richter scale devastated the city of Bam, 600 miles (1,000 km) southeast of Tehran, killing about 26,000 people.
It was the 13th major earthquake in Iran in the last 30 years.
Almost 87,000 people have died during that time, and countless more have been injured or made homeless.
|Search ON THIS DAY by date|