A 6.1 magnitude earthquake killed at least 37 and injured 850 in a sparsely populated area in south-west Iran on Tuesday, Iranian officials said. Rescue teams have been sent to the affected area, but darkness hampered immediate rescue operations.
The earthquake struck the town of Kaki 96 km southeast of Bushehr, a town on the Persian Gulf that is home to Iran's first nuclear power plant, built with Russian help. However, officials said the plant was undamaged.
''No damage was done to Bushehr power plant,'' Bushehr provincial governor Fereidoun Hasanvand told state TV. He said 37 people had died so far and 850 were injured, of whom 100 were hospitalised.
The plant's chief, Mahmoud Jafari, confirmed the site's condition to semi-official Mehr news agency, saying that it is resistant to earthquakes of up to magnitude eight.
Water and electricity was cut to many residents, said Ebrahim Darvishi, governor of the worst-hit district Shonbeh.
The UN's nuclear watchdog agency said on its website that it had been informed by Iran that there was no damage to the plant and no radioactive release, and based on its analysis of the earthquake, was not seeking additional information.
The International Atomic Energy Agency statement indicated that it was satisfied there was little danger.
Three helicopters were sent to survey the damaged area before sunset, said Mohammad Mozaffar, head of Iran's Red Crescent rescue department. He said the damage was particularly bad in the village of Baghan.
Kaki resident Mondani Hosseini said that people had run out into the streets out of fear.
Dozens of aftershocks have been reported by the official IRNA news agency since the earthquake, which occurred at 16:22 local time, 1728 IST.
Iran announced three days of mourning. The quake was felt across the Gulf in Bahrain, the United Arab Emirates and Qatar, where workers were evacuated from high-rise buildings as a precaution.
Some 10,000 people are thought to live in the affected area in more than 50 villages, two of which have reportedly been completely levelled.
Hasanvand said 700 houses have been damaged and 200 families affected.
The governor's office has sent generators to the area so rescue operation can continue overnight, the BBC's Mohsen Asgari in Tehran reported.
Seismologists said the quake struck at 16:22 local time (11:52 GMT) at a depth of 10km (6.2 miles). Iran's seismological centre in Bushehr province, linked to Tehran University, registered the quake at a magnitude of 6.1.
Iran's nuclear programme has roused concern among major powers that Tehran wants to build nuclear weapons - a charge Iran strongly denies – and led to strong US-led sanctions against the country.
Iran straddles a major geological fault line, making it prone to seismic activity. In 2003, an earthquake in the city of Bam left more than 25,000 people dead.