LOS ANGELES -- An earthquake with a magnitude of 7.0 shook parts of Northern California Thursday morning, temporarily forcing a tsunami warning that led to evacuations in some coastal areas of Northern California and the San Francisco Bay.

The notable quake struck an offshore area about 100 km northwest of Ferndale, a city in Humboldt County in Northern California with a population of more than 1,000, at 10:44 am local time, according to the U.S. Geological Survey (USGS).

It was initially reported as a 6.6-magnitude quake, and was upgraded to 7.0 by USGS. The depth of epicenter was identified at 0.6 km finally.

At least 5.3 million people in California were under a tsunami warning issued by the U.S. National Weather Service (NWS) minutes after the earthquake struck. However, the yellow alert only predicts localized but minimal damage.

The tsunami warning, extending from the Oregon state line down to the San Francisco Bay Area, was canceled by NWS about Thursday noon local time, saying, "No destructive tsunami has been recorded."

Residents up and down the Northern California coast, as well as into the Central Valley, reported feeling shaking.

About a dozen smaller aftershocks happened in Northern California, but there were no immediate reports of damage.