A moderate earthquake struck early Tuesday on the edge of the Salton Sea in Southern California's Imperial County, but there were no immediate reports of any injuries or damages.
The magnitude-4.8 quake struck at 4:55 a.m. at a depth of about 3.5 miles. It was centered two miles south of the small town of Bombay Beach on the eastern shore of the Salton Sea, about 90 miles east of San Diego.
The main quake was followed by at least 18 smaller aftershocks.
Tuesday's temblor was the largest in a swarm of earthquakes that have rattled the Salton Sea area since the weekend. More than 40 small quakes, most under magnitude-3, have been detected.
Scientists are keeping close watch on the increased earthquake activity because it is near a section of the San Andreas Fault that has not popped loose in over 300 years.
