“So far, there are seven dead and 30 injured receiving hospital treatment,” the official IRNA news agency quoted Qadami as saying.
However, an official said the temblor had “not created any problem for the activities of the power plant” at Bushehr, where Iran has its Russian-built reactor.
The quake’s epicentre was near Borazjan, around 60 kilometres (35 miles) from Bushehr.
The media said the quake had destroyed around 250 homes and businesses, while Dashtestan provincial Governor Alireza Khorani also spoke of damaged houses and electricity pylons.
Iran stands on several seismic fault lines.
In April, a 7.8 magnitude earthquake struck southeastern Iran and neighbouring Pakistan, killing 40 people.
A massive quake in December 2003 struck the southern city of Bam, killing 26,000 people and destroying its ancient mud-built citadel.
Iran’s Arab neighbours across the Gulf have often raised concern over the reliability of the Bushehr plant and the risks of radioactive leaks in case of a major quake.
But Iran and Russia insist it respects international standards under the supervision of the UN nuclear watchdog.
