According to the Seismological Center of the Institute of Geophysics of Tehran University, it struck at 0634 GMT some 100 kilometers, about 60 miles, east of Bushehr, the provincial capital.
The epicenter of the earthquake was about 18 km deep, the center added.
The quake was also felt in Bahrain and other areas around the Persian Gulf. There was no immediate report of damage or injuries.
Iran is one of the most seismically active countries in the world, being crossed by several major fault lines that cover at least 90% of the country. As a result, earthquakes in Iran occur often and are destructive.
The deadliest quake in Iran's modern history happened in June 1990. It destroyed the northern cities of Rudbar, Manjil, and Lushan, along with hundreds of villages, killing an estimated 37,000 people.
Bam in the country’s southeastern province of Kerman witnessed a strong quake in December 2003 which killed 31,000 people.