Two strong earthquakes struck northwest Iran on Saturday and at least 50 people were taken to hospital, but there were no reports of any deaths, Iranian media said.
The U.S. Geological Survey measured the first quake at 6.4 magnitude and said it struck 60 km (37 miles) northeast of the city of Tabriz at a depth of 9.9. km (6.2 miles) at 12.34 GMT.
It said a second earthquake measuring 6.3 struck 49 km (30 miles) northeast of Tabriz 11 minutes later at a similar depth. Three more lesser aftershocks have followed since then.
The second quake struck near the town of Varzgan, Fars news agency said. "The quake was so intense that people poured into the streets through fear," it said.
Fifty people in the town had been taken to hospital, Fars said.
Other reports said the earthquake had broken telephone communications, making rescue efforts more problematic.
Iran is straddled by several major fault lines and has suffered several devastating earthquakes in recent times, the last which struck the city of Bam in 2003, killing more than 25,000 people.