A 4.3 magnitude earthquake struck Berkeley, California, the U.S. Geological Survey (USGS) said. Nearby San Francisco also felt the strong tremor.
The quake struck around 2 kilometers (1.2 miles) east-southeast of Berkeley, the USGS recorded, and had a depth of 7.8 kilometers (4.8 miles).
It was initially recorded as a 4.6 magnitude tremor, but later revised down.
There was a green alert for shaking-related fatalities and economic losses.
"There is a low likelihood of casualties and damage," the USGS said.
Social media users living in the area said it was the strongest earthquake they had felt for a long time.
The area is close to the San Andreas Fault, a source of major earthquakes.
The San Andreas Fault runs about 750 miles from the Salton Sea in Southern California to Cape Mendoci