The US Geological Survey, reporting the magnitude of the quake at 6.3, said it struck 36 kilometres (22 miles) southeast of the city of Abdanan, near the border with Iraq.
According to state television, the quake occurred at 7:02 am (local time) near the town of Mour-Mouri. "Fortunately there have been no reports of deaths so far but there have been injuries and a great deal of material damage," a Red Cross official told the television.
The chief of the crisis committee for the area, Ahmad Karami, later said 250 people had been injured in the quake. In the village of Mour-Mouri, a number of homes and public buildings were damaged, according to the official IRNA news agency.
It added that damage also occurred in eight nearby villages. A number of people spent the night outside their homes after at least 44 smaller tremors struck the area yesterday, media reported. Iran stands on several seismic fault lines.
In April last year, a 7.8 magnitude earthquake struck southeastern Iran and neighboring 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.