An earthquake with a magnitude of 5.6 struck northern California on Monday, US seismologists said, but there were no immediate reports of casualties or damage.
The epicenter of the quake was located six miles (10 kilometers) from the town of Weitchpec, not far from the border with the state of Oregon, the US Geological Survey reported. It struck at a depth of 20 miles.
Earthquakes are regular events in California, mostly triggered by activity along the San Andreas Fault that runs through much of the western state, the most populous in the United States.
Geologists say a quake capable of causing widespread destruction is 99 percent certain of hitting California within the next 30 years. A magnitude 7.8 quake could kill 1,800 people, injure 50,000 more and damage 300,000 buildings.
A 6.7-magnitude earthquake in Los Angeles left at least 60 people dead and did an estimated $10 billion damage in 1994, while a 6.9 quake in San Francisco in 1989 claimed the lives of 67 people.