The quake hit an area around 240 kilometers (150 miles) southeast of the southern city of Shiraz in Fars province at 9:28 am (0558 GMT), Tehran's seismological institute was quoted as saying.

State television said the epicentre of the quake was near the towns of Zahrindasht -- also known as Haji Abad -- and Larestan.

The official news agency IRNA, quoting preliminary reports from the area, said there were no dead or injured but that a number of buildings were damaged.

It said the quake sent people running out of their homes in panic.

In July, two quakes measuring 5.6 and 5.8 on the Richter scale killed two people and injured more than 20, while damaging 4,299 houses and more than 40 public buildings.

However, the human toll was low as those quakes occurred at night, when many people in the area sleep on their roofs to cool down from the searing heat of the daytime.

Since July, the area has been jolted by more than 200 aftershocks.

Earthquakes are frequent in Iran, which is criss-crossed by a large number of seismological faultlines. Close to a thousand have hit the country since 1991, killing about 17,600 people and injuring another 53,500, according to figures from IRNA.

TERRA.WIRE