Three still missing in California's deadly mudslides

The number of people missing from last week's deadly Southern California mudslides fell to three on Monday (Jan 15) as hundreds of rescue workers searched for survivors from the rain-driven slides that killed 20 people.

A 53-year-old transient, John Keating, had been listed among the four still missing but was found safely in Ventura, California, with his dog, the Santa County Sheriff's Office said in a statement.

Three people ages 2 to 28 are still listed as missing after sheriff's detectives investigated more than 100 missing persons cases, the statement said.

Emergency officials said hopes were diminishing that they would pull more survivors from the ravaged landscape of hardened muck, boulders and twisted debris left behind by the Tuesday mudslides that scoured a landscape already barren from last year's record-setting wildfires.

The mudslides that scoured the affluent community of Montecito, 137km northwest of Los Angeles, caused the greatest loss of life from a California mudslide in at least 13 years.

Ten people perished in January 2005 when a hillside saturated by weeks of torrential rains collapsed in the seaside hamlet of La Conchita, 29km southeast of Montecito, burying more than a dozen homes in seconds.

The White House on Monday said that President Donald Trump had been briefed on the situation.

"The President and First Lady extend their deepest sympathies to the families affected, their appreciation for the first responders saving lives, and their prayers for those who remain missing," the White House said in a statement.

Another 900 emergency personnel arrived this weekend to join the relief effort conducted by more than 2,100 personnel from local, state and federal agencies.

The destruction covered 78 square km, leaving 65 single-family homes demolished and more than 450 damaged. Nearly 30 commercial properties were damaged or destroyed, officials said.

As a precaution against further slides, officials have ordered residents in most of the southeastern corner of Montecito to leave their homes for what was likely to be one or two weeks.