LOS ANGELES－Authorities in southern California said on Thursday that dozens of residents were still unaccounted for after powerful mudslides that have killed 17 people, including four children, and destroyed homes in a region already pummeled by massive wildfires.

Heavy rain on Tuesday, which followed 10 months of drought, sent sticky mud and debris flowing from the hills into Montecito and other towns in Santa Barbara County, northwest of Los Angeles.

"There are 43 people we're now looking into and investigating to see if they actually are missing," Santa Barbara County sheriff Bill Brown said, adding: "It's a constantly moving number."

Authorities emphasized the situation was still fluid. Earlier in the day, officials put the number of missing at just eight.

Brown said those unaccounted for could yet be located, but warned that the death toll could rise. "There are mothers, fathers, grandfathers, siblings, and the list goes on and on,"

Terrifying wildfires forced people to evacuate in December, with the mudslides striking just two weeks after they returned.

The fires burned most vegetation, leaving perfect conditions for the latest disaster to unfold.

With clean-up operations underway, workers were battling the viscous mud on the streets of Montecito on Thursday, while in other areas efforts continued to restore power.

"It was a scary night," said local resident Jane Barretsaid. Her doctor, the leader of her children's Boy Scout group and a former neighbor were among the dead.

Barret added it would "take a lot of time" to get over the natural disasters that have struck the area over the past two months.

The highest rainfall was recorded at 13 centimeters in Ventura County, according to the National Weather Service, but forecasts for the next week do not predict rain.

Residents were rescued by helicopter from the roofs of their homes－with some later returning to recover valuable belongings and pets.

Shocked by the damage, they took photos of their now-destroyed houses, with many describing the storm as similar to a stampede or an out-of-control train.

Greg Duimovich said his house had "never shaken so much" from a rainstorm.

About 50 kilometers of the 101 Freeway, which connects California to the south, remained blocked by mud.