A shallow 5.1-magnitude earthquake rocked the Los Angeles area, the US Geological Survey said, causing some minor damage and stopping rides at Disneyland.
The quake on Friday was the biggest in the Los Angeles area for six years, since a 5.5-magnitude earthquake struck nearby Chino Hills in 2008. Friday's quake came after one measuring 4.4 earlier this month.
Emergency services said they had calls about gas leaks and water main breaks, while some residents said objects fell from walls and shelves, but there were no immediate reports of injuries.
Disneyland shut down rides as a precaution, according to NBC4 television. Some said they were stuck on rides.
The quake's epicentre was near La Habra, 35 kilometres southeast of downtown Los Angeles, and could be felt across the metropolitan area, including in Hollywood. Residents in La Habra sent out pictures on social media showing broken vases, toppled furniture and items scattered around their homes.
US Geological Survey seismologist Lucy Jones said the 5.1 quake has a 5 per cent chance of being a foreshock of an even larger quake.
"There could be even a larger earthquake in the next few hours or the next few days," Jones said at the California Institute of Technology.
The quake, which was preceded and followed by a number of smaller ones, came after a 4.4-magnitude earthquake jolted Angelenos out of bed on March 17.
Friday's quake was felt in Los Angeles as a lower rumbling which lasted up to half a minute, rather than a sharp jolt.
Tom Connolly, a Boeing employee who lives in La Mirada, the next town to La Habra, said the quake lasted about 30 seconds.
"We felt a really good jolt. It was a long rumble and it just didn't feel like it would end," he said. "In the beginning it shook really hard, so it was a little unnerving."
California has long braced for the "big one".
Seismologists say a quake capable of causing widespread destruction is 99 per cent certain to hit California in the next 30 years.
Additional reporting by Associated Press