Another powerful storm hit California on Saturday night, forcing thousands to flee their homes, killing at least two people and rupturing a dam in coastal Monterey County.

"We were hoping to avoid this situation, but the worst case scenario happened with the Pajaro River flooding and the dam cracking around midnight," Monterey County official Luis Aliu said Saturday via Twitter.

Residents confirmed to AFP that local fire officials told them in the middle of the night to evacuate their homes.

"The noise of the sirens woke us up," said Musa, who has lived in the area for about 20 years and preferred to give his first name only.

He added that officials came later and knocked on his door several times, but he decided to wait until five o'clock in the morning before leaving with his wife, as the flood waters rose in the vicinity of the house.

The National Weather Service said the area remains under a flood warning on Saturday afternoon.

Pictures posted on Twitter showed guards rescuing residents trapped in their cars due to rising water.

At least one road was damaged in Santa Cruz County, north of Monterrey.

Residents of several towns, mostly in the north, were ordered to evacuate.

A series of unusually severe storms has been hitting California for weeks.

In Pajaro, the Fire Department and National Guard on Saturday used drones to survey flooded areas and search for people stranded in their homes, AFP correspondents reported.

For his part, US President Joe Biden approved Friday's declaration of emergency in California, paving the way for accelerating federal assistance to the state.

Governor Gavin Newsom said California is "using every tool available to protect residents from the severe and deadly storms that batter our state."

Storms in January killed 20 people.