A moderate earthquake and some smaller aftershocks rattled the San Francisco Bay area before sunrise Monday, the U.S. Geological Survey (USGS) reported. The magnitude-4.0 earthquake hit at 5:33 a.m. local time (1233 GMT) and was centered 13 kilometers northeast of San Francisco in the city of El Cerrito, USGS said. It was followed by at least two small aftershocks, including a magnitude-2.0 shortly after 6:00 a.m. Shaking was felt throughout the Bay Area, from Santa Rose in the north to Santa Cruz in the south. There were no immediate reports of damage or injuries. Bay Area commuter trains were briefly delayed for tracks to be inspected.