There are no immediate reports of damage or casualties.
The quake hit an area around the town of Arzuieh in Kerman Province.
Iran, which spans several major faultlines in the earth's crust, is prone to frequent earthquakes.
In December 2003, the southeastern city of Bam was razed by a quake that left more than 20,000 people dead.
(AFP, AP, Reuters, dpa)
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