A magnitude 5.9 earthquake on Thursday struck Iran's southern province of Bushehr, which is home to a nuclear power plant, state television reported, but there were no immediate reports of casualties or damage.
Many houses in rural parts of the province are made of mud bricks, which have been known to crumble easily in quake-prone Iran.
"The quake hit the Kaki area in the province this morning," the television said.
The semi-official Tasnim news agency said the quake was felt in Bahrain and some other Gulf states.
It said the depth of the quake was 18 km. It gave no further details.