Some San Francisco Bay area residents were awakened by an earthquake and some smaller aftershocks.
The U.S. Geological Survey reports the magnitude-4.0 quake struck at 5:33 a.m. Monday and was centered 8 miles northeast of San Francisco in the city of El Cerrito. The shaking was felt throughout the Bay Area, from Santa Rosa in the north to Santa Cruz in the south.
The temblor was followed by a couple small aftershocks, including a magnitude-2.0 at shortly after 6 a.m.
Bay Area commuter trains were briefly delayed after the quake to inspect the tracks.
The California Highway Patrol, San Francisco police and El Cerrito police say they haven't received any reports of serious injury or damage.