A strong earthquake hit deep under the Pacific Ocean offshore northern California Saturday afternoon, interrupting power, shaking homes and cracking ceilings but causing no reported human injuries, dpa reported.
The 6.5-magnitude quake hit at 0028 GMT Sunday (4:28 pm local time) about 400 kilometres north of San Francisco, off the coastal town of Ferndale, population about 1,200, the US Geological Survey said late Saturday.
The quake hit about 35 kilometres west of the coastal town of Ferndale, and about 16 kilometres under the ocean's surface, the USGS said. There was no tsunami warning.
Four aftershocks about 3.8 magnitude followed the major quake.
The Los Angeles Times reported that about 25,000 customers were without power. Ferndale is just south of the larger town of Eureka.
"We've got some downed power lines as well as some other damage to other equipment," Jeff Smith, a spokesman for Pacific Gas & Electric Co told the newspaper.
Firefighters were checking out reports of numerous gas leaks.
Earlier this week, a 4.1-magnitude earthquake rattled San Francisco, preceded by a 2.8-magnitude quake in the same area the day before.