No casualty or damage has been reported by far.
"It's ongoing activity there".
Also, according to the USGS, the earthquakes hit at a depth of about six miles.
The U.S. Geological Survey says three earthquakes with a magnitude of around 5 have struck along the Iran-Iraq border. In Baghdad, people felt a quake shake the Iraqi capital, followed by what felt like aftershocks.
The region, largely rebuilt in recent decades after Iran and Iraq's ruinous 1980s war, saw many buildings collapse or sustain major damage in the November quake.
On November 12, a 7.3-magnitude quake hit Kermanshah, killing more than 620 people and injuring around 10,000 others, mainly in the city of Sarpol-e Zahab and the nearby villages.
There were no immediate reports of injuries or damage.
Iranian media are reporting that a magnitude 5.1 natural disaster has jolted the country's southern province of Kerman. Earlier in the morning, a 5.1-magnitude quake had rattled Kerman province in southern Iran.
Iran sits on major seismic fault lines and is prone to frequent earthquakes.
A magnitude 7.3 natural disaster in the same area in mid-November killed at least 530 and injured more than 8000.
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.
Kerman has recently seen several quakes, ranging in magnitude from 4 to 6.2.