(Reuters) - A magnitude 5.8 earthquake struck northwestern Iran early on Friday, the U.S. Geological Survey said, but Iranian state TV said there were no immediate reports of any damage or casualties.
The quake struck at 2:17 a.m. (2247 GMT) and Iran's IRNA news agency said the tremor was relatively strong and caused many people to run out of their homes in panic in the middle of the night.
"So far there have been no reports of damages or casualties," Iranian state TV said, adding the quake was felt in several towns and cities.
The epicenter of the quake, initially reported as a magnitude 6.0 by the European-Mediterranean Seismological Centre
(EMSC), was located 83 km (52 miles) southwest of Ardabil at a shallow depth of 10 km (6.2 miles), the USGS said.
EMSC said the quake was felt by some 20 million people.
(Reporting by Sandra Maler in Washington; Additional reporting by Mohammad Zargham in Washington and Parisa Hafezi in Dubai; Editing by Peter Cooney)