The semi-official ISNA news agency says the temblor today rocked the village of Hojedk, about 700 kilometres south of Tehran. It says the quake's depth was 9 kilometres.
There were no immediate reports of casualties or damage. The province has been hit by several medium-intensity earthquakes in recent days.
Iran is prone to near-daily earthquakes as it sits on major fault lines. In November, a 7.2-magnitude quake hit western Iran, killing more than 600 people. In 2003, a 6.6- magnitude quake flattened the historic city of Bam, killing 26,000 people.