Magnitude 3.1 earthquake hits near San Francisco

SAN RAMON, Calif.-- A magnitude 3.1 earthquake struck the San Ramon area of California on Sunday afternoon, according to the U.S. Geological Survey, reports CBS San Francisco.

The quake struck at 3:31 p.m. Sunday, after more than a dozen small quakes struck the area the day before, on the anniversary of the Loma Prieta earthquake, reports CBS SF.

Sunday's quake struck at a depth of about six miles.

No damage or injuries were immediately reported.