An earthquake shook southern Iran early Thursday morning, but there were no immediate reports of casualties or damage.
Radio reports said residents of the southwestern city of Bandar Abbas poured into the streets after the quake hit.
The U.S. Geological Survey said the quake struck at 1:32 a.m. local time and had a magnitude of 5.6. It was centered about 35 miles southwest of Bandar Abbas, or about 650 miles southeast of Tehran, the capital.
No other details were immediately available.
Even moderate quakes have killed thousands of people in the past in the Iranian countryside, where houses are often built of bricks.
In March, three strong earthquakes and several aftershocks jolted western Iran overnight, killing at least 66 people. In February last year, a 6.4-magnitude quake rocked the town of Zarand in southern Iran, killing 612 people and injuring more than 1,400.
Some 26,000 people were killed by a 6.6-magnitude quake that flattened the historic southeastern city of Bam in the same region in 2003.