North-West Iran was hit by two powerful earthquakes,leaving at least 180 people dead and more than 1,300 injured, officials say.
The quakes struck near the border of city of Tabriz and the town of Ahar, however, most of the casualties are thought to be in outlying villages.
Reports say phone lines to many villages have been cut off, making rescue efforts harder.
The casualty toll and the scale of the disaster was still emerging. Officials had to use radios because of disrupted telephone communications in the region and dispatched helicopters to remote villages.
The US Geological Service measured the quakes at magnitude 6.4 and 6.3.
“The quake has created huge panic among the people,” one resident of Tabriz told the BBC. “Everyone has rushed to the streets and the sirens of ambulances are everywhere.”
The towns of Haris and Varzaqab in East Azerbaijan province were among those that suffered casualties, Khalil Saei, local crisis committee chief, told state TV, according to the Associated Press.
Officials say at least four villages have been completely destroyed, with another 60 villages suffering damage ranging from 50% to 70%.
Officials warn that the death toll may rise.
A provincial official has warned people in the region to stay outdoors overnight because of the risk of aftershocks.
Allahverdi Dehqani, a lawmaker in Varzaqan, confirmed that “most of the villages around Varzaqan have been damaged.”
Rescue operations were continuing into the night.
Tehran University’s Seismological Centre said the first earthquake hit at 4:53 pm (1223 GMT) with an epicentre just 60 kilometres (40 miles) from Tabriz, close to the town of Ahar, and at a depth of 10 kilometres.
The second — a big aftershock — rumbled through just 11 minutes later from nearly the same spot. A series of 17 smaller aftershocks rating 4.7 or below rapidly followed.
Iran sits astride several major fault lines and is prone to frequent earthquakes, some of which have been devastating.
The deadliest was a 6.6-magnitude quake which struck the southern city of Bam in December 2003, killing 31,000 people — about a quarter of the population — and destroying the city’s ancient mud-built citadel.
Lawmaker Abbas Falah said people in the region are in need of bread, tents and drinking water.
“There were around 10 aftershocks, which lasted a total of 10 minutes.”
The two earthquakes came within minutes of each other, according to seismology experts at Tehran University.
We will bring you more information covering this major Middle-East disaster as soon as we can confirm reports.