A strong 6.0-magnitude earthquake jolted California early Sunday morning, the US Geological Survey said, though there were no immediate reports of deaths or serious damage.
The quake struck at 3:20 am (1020 GMT) northwest of American Canyon, California, USGS said, at a depth of just 6.7 miles (10.8) kilometers from the surface.
Residents of the cities of San Francisco, some 40 miles away, and Davis, just over 70 miles away, quickly took to Twitter reporting feeling the quake.