A 5.6-magnitude earthquake shook Iran's central desert on Monday, residents and state television said.
The quake was felt in the capital, Tehran and in several other cities for about seven seconds starting at nearly 6 p.m. (14:29 GMT), residents said.
Its center was near the central Iran city of Qom, the location of a revered Shiite shrine. State television had no immediate reports of casualties or damage.
The quake's epicenter was 18.64 miles below the earth's crust, state TV said. Life appeared to have returned to normal by late afternoon in the capital.
Magnitude-5 quakes have been known to topple buildings in densely populated areas, but the quake on Monday seemed to have hit hardest in a largely desertic zone.
Iran is located on seismic fault lines and is prone to earthquakes. It experiences at least one slight earthquake everyday on average.
In March 2006, three earthquakes and nine aftershocks hit western Iran, in quick succession, killing at least 70 people and injuring about 1,200 .