State radio said residents of the southern port city of Bandar Abbas poured into the streets after the 4.9-magnitude quake hit at 2:56 a.m. local time Wednesday.
The broadcast said there were no reports of deaths in the quake, which hit 850 miles (1,367 kilometers) south of the capital. Bandar Abbas is one of Iran's key ports and home to a large oil refinery that primarily serves the domestic market.
Iran is located on seismic fault lines and is prone to earthquakes. It experiences at least one slight earthquake everyday on average.
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.
