SAN FRANCISCO (AP) _ A moderate earthquake shook the San Francisco Bay area early today, waking people and disrupting some transit trains. There were no reports of damage or injuries.

The U.S. Geological Survey put the magnitude of the 4:16 a.m. quake at 4.1. It said the epicenter was about three miles east-southeast of Richmond, which is about 10 miles northeast of San Francisco.

Service on Bay Area Rapid Transit system trains from Richmond was halted because of an electrical problem caused by the quake, but it was quickly restored. Other lines were running slowly while engineers checked tracks for damage.

In Oakland, Police Officer Jason Kaiser said the department had not received any calls for assistance.

``It felt pretty strong,'' he said. ``But it was really quick. A good little shake.''