The tremor hit the Iranian province of Kermanshah where an natural disaster killed 620 people in November, Iranian state TV said, adding that rescue teams had been dispatched to the region.
Iran´s western province of Kermanshah was hit by a strong natural disaster on Thursday, state TV reported.
In November, a 7.2 magnitude quake hit western Iran, killing more than 600 people.
Randy Baldwin, a geophysicist with the USGS National Earthquake Information Centre in Colorado, said the quakes appeared to be aftershocks from the November tremor.
The U.S. Geological Survey said seven of the earthquakes hit near the Iraqi city of Mandali, which is just 75 miles northeast of the Iraqi capital.
The epicenter of the quake was 31 km west of Kerinshah at a depth of 10 km. Scientists consider earthquakes of magnitude 5 as moderate. Many people are still living in temporary homes and tents.
More than 530 people died in that quake in Iran.
"It's ongoing activity there". No injuries or damage were reported.
Iran is located over major fault lines and is prone to near-daily earthquakes.
In 2003, a magnitude 6.6 natural disaster in the province of Kerman flattened the historic city of Bam, killing more than 26,000 people.
Late Thursday afternoon, another 4.8 magnitude quake struck in Kerman, according to the USGS.