The country's seismological center said the magnitude-6 quake struck at 3:30pm (1100GMT) and was centered about 1350km south of the capital, Tehran, in the region of Bandar Abbas.
Bandar Abbas is one of Iran's main ports and is home to a large oil refinery that primarily serves the domestic market. The city's residents, reached by telephone, said the quake caused panic and prompted many to run to parks.
"When the quake struck, it was like a snake bite," said Hani Shokouhi, a resident of Bandar Abbas. "Then, the chandeliers and drawers were moving from one side to the other in the house."
Shokouhi said many residents remained in the streets, too afraid to return to their homes.
Qeshm island in the Persian Gulf was hit hardest, according to the state TV report, which quoted Yasser Hazbavi, a local disaster management official. Hazbavi said the shaking lasted 30 seconds, but he gave no details on the extent of the damage there.
The quake caused a power outage and minor damage on the island, the report said.
Ten aftershocks were registered, each with a magnitude of 4.7 or less, state TV said, quoting an official at the seismological center whom it identified only by a last name, Rezapour.
Abdolkarim Setareh, a local official in the town of Bandar-e-Khamir, also near the quake's epicenter, said extensive damage was unlikely.
"Houses in this region have been built in recent years and are resistant to earthquakes. Only minor damage has been reported from a dozen villages so far," he told The Associated Press by phone.
The U.S. Geological Survey estimated the quake's strength at magnitude 6.1.
Across the Persian Gulf waters, residents in Dubai and neighboring emirates reported feeling shaking that lasted less than a minute.
The tremors sent office workers rushing out of some of the high-rise towers that dot the skyline in the city-state's commercial center.
All buildings in the Dubai International Financial Center were evacuated, the DIFC said. More than 700 companies are registered at the DIFC, located in the city's commercial district.
Dubai Civil Defence officials said they received several calls from panicked residents, saying their beds were shaking and their furniture was collapsing.
"My bed was hitting against the wall," said Rheanne Anderson, a Canadian teacher living in the nearby emirate of Ras al-Khaimah. "There was definitely some shaking."
There were no reports of damage or casualties in the Emirates.
Iran is located on seismic fault lines and experiences at least one slight earthquake every day on average.
In February 2005, a magnitude-6.4 quake rocked the town of Zarand in southern Iran, killing 612 people and injuring more than 1,400.
A magnitude-6.6 quake flattened the historic city of Bam in the same region in December 2003, killing 26,000 people.
