SAN RAMON, Calif. (AP) — The U.S. Geological Survey reports that a small earthquake hit the San Ramon area early Saturday morning, the latest in a series of small quakes to hit the region recently.

The agency says the magnitude-3.2 earthquake hit about 12:43 a.m. and had its epicenter about a half mile from San Ramon, which is southwest of Sacramento.

The earthquake is the latest of a swarm of small earthquakes that has been rattling the area, with more than 200 recorded since last week.

All the previous quakes were centered around the city of San Ramon on either the Calaveras Fault or offshoots of it. The largest struck Monday and was logged as a magnitude-3.5, according to the U.S. Geological Survey. No injuries or major damage have been reported.

Experts say such swarms are not unusual or cause for extra concern.

The earthquake was too small to be felt in Sacramento.