According to the Seismological Center of the Geophysics Institute of University of Tehran, the quake was registered at 20:56:49 local time.
The epicenter of the quake was registered at 58.43 in longitude and 37.20 in latitude.
There was no report of likely casualties or damages.
Iran sits astride several major faults in the earth's crust, and is prone to frequent earthquakes, many of which have been devastating.
The worst in recent times hit Bam in Kerman province in December 2003, killing 31,000 people - about a quarter of its population - and destroying the city's ancient mud-built citadel.
The deadliest quake in the country was in June 1990 and measured 7.7 on the Richter scale. About 37,000 people were killed and more than 100,000 injured in the northwestern provinces of Gilan and Zanjan. It devastated 27 towns and about 1,870 villages.
In August 2012, two quakes in northwestern Iran also claimed the lives of 306 people and injured more than 4500 others.