There were no immediate reports of damage or casualties.
Iranian state television reported on January 2 that a 5.8-magnitude earthquake hit the town of Sangan, which has a population of about 10,000.
“We have not received any reports of casualties at this moment, but a large area has been affected, which our survey teams are investigating,” said Hojjatali Shayanfar, the head of the provincial emergency department.
The European-Mediterranean Seismological Center reported that the quake measured 5.5 on the Richter scale and hit 253 kilometers south of the Iranian city of Mashhad and 169 kilometers west of the Afghan city of Herat.
Earthquakes are common in the region.
In October 2015, a quake killed more than 400 people and left several thousand homeless in Afghanistan, Pakistan, and India.