A small earthquake rattled the San Francisco Bay Area early Thursday, but there were no immediate reports of any problems.

The U.S. Geological Survey says the magnitude 3.5 temblor struck at 12:06 a.m. and was centered near San Ramon and about 15 miles east of San Francisco. The quake occurred 6 miles underground.

The Contra Costa County Sheriff's office said it had no reports of any injuries or damages from the quake.

The USGS website had hundreds of hits from people in the Bay Area saying they felt it.