Washington: An earthquake of 6.0 magnitude rocked northern California on Sunday, injuring an undetermined number of people and cutting electric power across the region.
It was the largest temblor registered in the area since the 7.0 magnitude Loma Prieta quake in 1989, said the US Geological Survey (USGS).
The epicentre of the quake, which occurred about 3.20 a.m. local time (10.20 a.m.), was located 6 km northwest of American Canyon, a small town about 64 km north of San Francisco.
"The 6.0 M (magnitude) near the Bay Area this morning was the largest quake to hit that area since the Loma Prieta earthquake almost 25 years ago," the USGS said in a post on its official Twitter account.
There are reports of ‘numerous' injuries and extensive structural damage in Napa, Efe reported citing Napa Fire Department chief Steve Becker as saying in daily San Francisco Chronicle.
Becker, however, did not provide any further details.
A fire in a mobile home park destroyed at least three homes in Napa, where the quake caused widespread damage and filled some of the streets with bricks, broken windows and other wreckage, Becker said.
There are multiple reports of power outages, gas leaks and flooding in the San Francisco Bay Area and at least 15,000 Pacific Gas and Electric Co. customers are without electricity in Vallejo, Napa, Rohnert Park, Santa Rosa and Sonoma.
The earthquake was followed half an hour later by about half a dozen minor aftershocks, the largest of which was measured at 4.0 magnitude, the USGS said, adding that there is a 54 percent chance that a strong aftershock will occur within the next week.