An earthquake with a preliminary magnitude of 5.2 shook Southern California early this morning.

There were no reports of injuries or signficant damage in Los Angeles, Orange, and San Diego counties, fire officials said, but the shaking served as a wake-up call for many Southern Californians.

The quake was centered about 14 miles northwest of Borrego Springs -- about 90 miles east of San Diego -- and hit just after 1 a.m., according to the U.S. Geological Survey.

Residents reported feeling shaking from the earthquake in San Diego, West Los Angeles, Riverside and Woodland Hills, ABC Los Angeles station KABC reported. Officials said the earthquake set off a lot of alarms at businesses.

The earthquake occurred along the San Jacinto Fault, historically the most active fault in Southern California, according to seismologist Lucy Jones

Source :WAM