Bushehr's governor Fereydoon Hassanvand said eight people were killed and 45 others wounded.
According to the Iranian Seismological Center, the quake hit Borazjan, located 715 kilometers (444 miles) south of the Iranian capital, Tehran, at 5:21 p.m. local time (1351 GMT) on Thursday.
Its epicenter was located at 29.29 degrees of northern latitude and 51.37 degrees of eastern longitude, at a depth of five kilometers.
The strong earthquake was followed by at least five aftershocks, the strongest of which had a magnitude of 3.4.
SHI/SHI