BEIJING, June 20 -- A 5.0-magnitude earthquake hit about 195 kilometres off the northern California coast early Sunday morning, the fifth moderate or strong tremor to hit the state in a week, according to the US Geological Survey.

    The quake struck at 2:27 a.m. PDT, and its epicenter was 282 miles northwest of San Francisco, the Geological Survey said.

    A Humboldt County Sheriff's Department dispatcher said there were no immediate reports of damages or injuries.

    A 7.0-magnitude quake struck about 130 kilometres off the coast Tuesday night prompting an hour-long tsunami warning from the California-Mexico border north to Vancouver Island, B.C.

    Two other quakes in the past week had inland epicenters in Southern California.

    A patchwork of faults crisscrosses California, and the Southern California Earthquake Center recently estimated a major earthquake beneath Los Angeles could cause up to 18,000 deaths and $250 billion in damage.

    Seismologists have said that earthquakes coming in clusters are not necessarily a sign that a major quake is coming.

    (Agencies)