A magnitude-4.1 earthquake struck near the San Jacinto fault zone, approximately nine miles from Moreno Valley, according to the U.S. Geological Survey.
The temblor struck at 7:44 a.m. on Wednesday and was lightly felt in northern San Diego County.
The San Jacinto fault is known as the most active earthquake fault in southern California, according to USGS. Scientists have warned the fault zone is overdue for a magnitude 7.0 earthquake. The last significant quake to strike the region was a magnitude 5.4 temblor in July 2010.
There are no reports of damage or injury.