The Los Angeles Times reported the quake happened at 9.55 a.m and its epicenter was in the desert near Anza, southeast of LA, the US Geological Survey reported.
The late morning quake was felt sharply in the local area, and was also felt about 100 miles away in downtown Los Angeles, San Diego and in Orange County, AP reported.
Updated reports downgraded the quake's strength to a magnitude 4.7, the Mercury News reported.
Palms Springs police Sgt Harvey Reed told the newspaper the department has received no reports of damage or injuries.
Anza is about 30 miles east of Temecula. There were no immediate reports of damage. The US Geological Survey noted several aftershocks.