(CNN) -- At least four people were killed Tuesday afternoon in a powerful earthquake that struck southern Iran, in the vicinity of a key nuclear facility, Iran's state-run Press TV announced.
A 6.3-magnitude earthquake was centered about 89 kilometers southeast of Bushehr -- home to a nuclear plant -- the U.S. Geological Survey said.
Iran's Fars news agency said the quake measured at 6.1 magnitude.
The quake "ruined" the city of Kaki, which is near the epicenter, the state-run IRNA news agency said. Relief workers have been sent to help local officers in various rescue operations in parts of Bushehr province, an official with Iran's Red Crescent Society said, according to IRNA.
State-run Press TV reported that the network has spoken to officials at the Bushehr plant and that there were no problems there. Press TV warned that officials were indicating the number of casualties is expected to rise.
The quake was at a depth of 10 kilometers, according to the USGS.
At least three strong aftershocks struck the same area later Tuesday, the USGS said.
The CNN bureau in Dubai said that the quake was felt in the United Arab Emirates, across the Persian Gulf from Iran, and that some buildings in Abu Dhabi were evacuated.
The quake was also felt in Qatar and Bahrain, according to a CNN journalist in Abu Dhabi, who said some businesses have sent their employees home for the day.
The damage that earthquakes with magnitudes of 6.0 to 6.9 can produce varies widely. Near the epicenter, quakes on the lower to middle parts of that range could leave negligible to slight damage in buildings of good design, and considerable to great damage -- such as broken or fallen walls -- in poorly designed structures, according to the USGS.
CNN's Phil O'Sullivan and Schams Elwazer contributed to this report.