The Iranian Seismological Center said the epicenter of Tuesday's quake was near the eastern border with Pakistan. The U.S. Geological Survey recorded a 7.8-magnitude quake followed by a magnitude 4.1 aftershock.
Iran's state-funded broadcaster Press TV reports "several" people may be dead and at least 100 were injured. Russia authorities who contracted the Bushehr nuclear power plant said the quake didn't damage the facility.
A magnitude-6.3 earthquake struck about 55 miles from Bushehr last week. The International Atomic Energy Agency said it received verification from the Iranian government the facility wasn't damaged and no radiation was released from the site following the quake.
Iran in September started operations at the Bushehr nuclear plant with the help of Moscow. Russia operates and supplies fuel for the plant.
Last week, Iran announced it was preparing for additional nuclear work following multiparty negotiations in Kazakhstan. Iranian President Mahmoud Ahmadinejad said his country is a nuclear power and that title wasn't up for debate by its adversaries.
Iran is suspected of pursuing the technology needed to manufacture a nuclear weapon, an allegation the government denies.