Los Angeles, Dec 6 (IANS): More than five million people in northern California in the US were under a tsunami warning after a 7.0-magnitude earthquake hit the area.

The notable quake struck the area around Ferndale, a city in Humboldt County in northern California, at 10:44 a.m. Eastern Time on Thursday, according to the US Geological Survey (USGS).

It was initially reported as a magnitude 6.6 quake, but then was upgraded to 7.0 by the USGS, Xinhua news agency reported.

At least 5.3 million people in California were under a tsunami warning issued by the US National Weather Service (NWS) after the earthquake struck, according to the USGS.

The tsunami warning extends from the Oregon state line down to the San Francisco Bay Area, according to the NWS.

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

There were no immediate reports of any damage.

The San Francisco Bay Area Rapid Transit District, known as BART, has stopped traffic in all directions through the underwater tunnel between San Francisco and Oakland, local media reported.