(CNN) Searchers in California sifted through mud-caked debris Monday for three people missing in mudslides that have killed at least 20 and walloped Montecito, the Santa Barbara County Sheriff's Office said.

Hampered by blocked roads, downed trees and power lines, deputies searched for John "Jack" Cantin, 17 and Faviola Benitez Calderon, 28

Thousands of people at the vigil to remember those 20 lost in the Montecito flood. Santa Barbara County Courthouse Sunken Gardens. #MontecitoFlooding #805Strong #santabarbarastrong @CHP_HQ @CHP_Ventura @CHPMoorpark @SBCityOES_RH @csbenespanol @CHP_Coastal pic.twitter.com/4nyj11UzwI

The mudslides came in the early morning hours of last Tuesday, destroying an estimated 65 homes and damaging hundreds of others, the California Department of Fire and Forestry Protection said.

The rain poured down on hillsides charred by recent wildfires , which burned vegetation that otherwise could make the terrain more resistant to mudslides.

burned more than 281,000 acres in Santa Barbara and Ventura counties from early December into this month. It wasn't fully contained until Friday. The Thomas Fire -- the largest wildfire in California's recorded history --burned more than 281,000 acres in Santa Barbara and Ventura counties from early December into this month. It wasn't fully contained until Friday.

For days, rescuers searched frantically for the missing after mud and boulders barreled into neighborhoods in and near Montecito, an affluent seaside community east of Santa Barbara. The mudslides demolished homes and left roads impassable.

Now, what had been a search-and-rescue operation authorities is a search-and-recovery undertaking. The crews probably won't be hampered by bad weather most of this week. The first chance of rain will come Thursday night to Friday and it is estimated to amount generally to less than a third of an inch, CNN meteorologists said.

Photos: Deadly mudslides in Southern California An aerial view of Montecito, California, shows mudflow and debris on Wednesday, January 10, 2018. Heavy rains unleashed deadly mudslides Tuesday that damaged or swept away dozens of homes in Southern California. Hide Caption 1 of 18 Photos: Deadly mudslides in Southern California A damaged home is seen in Montecito on January 10, 2018. Hide Caption 2 of 18 Photos: Deadly mudslides in Southern California Part of a structure sits in a tree after being knocked off its foundation by a Montecito mudslide on January 10, 2018. Hide Caption 3 of 18 Photos: Deadly mudslides in Southern California Emergency personnel carry a woman from a collapsed house after a mudslide in Montecito on January 9, 2018. Hide Caption 4 of 18 Photos: Deadly mudslides in Southern California Kerry Mann navigates the large boulders and mudflow that destroyed her friend's home in Montecito. Hide Caption 5 of 18 Photos: Deadly mudslides in Southern California A view of the 101 freeway from Olive Mill Road in Montecito. Hide Caption 6 of 18 Photos: Deadly mudslides in Southern California Phillip Harnsberger crosses through mud from a flooded creek in Montecito on January 9, 2018. Hide Caption 7 of 18 Photos: Deadly mudslides in Southern California Mud fills the interior of a destroyed car in Burbank on January 9, 2018. Hide Caption 8 of 18 Photos: Deadly mudslides in Southern California Runoff water from a creek floods Highway 101 in Montecito on January 9, 2018. Flooding forced many heavily traveled roads to close. Hide Caption 9 of 18 Photos: Deadly mudslides in Southern California Reilly, a search dog with the Santa Barbara County Fire Department, looks for victims in Montecito on January 9, 2018. Hide Caption 10 of 18 Photos: Deadly mudslides in Southern California A firefighter clears debris in Los Angeles on January 9, 2018. Hide Caption 11 of 18 Photos: Deadly mudslides in Southern California A van is stuck in the mud in the Sun Valley neighborhood of Los Angeles on January 9, 2018. Hide Caption 12 of 18 Photos: Deadly mudslides in Southern California A police vehicle drives across a flooded side road in Montecito, near the San Ysidro exit of Highway 101 on January 9, 2018. Hide Caption 13 of 18 Photos: Deadly mudslides in Southern California Mud covers a road in Burbank on January 9, 2018. Hide Caption 14 of 18 Photos: Deadly mudslides in Southern California Los Angeles firefighters work amid floodwaters and mud on January 9, 2018. Hide Caption 15 of 18 Photos: Deadly mudslides in Southern California A member of the Long Beach search and rescue team looks for survivors in a car in Montecito on January 9, 2018. Hide Caption 16 of 18 Photos: Deadly mudslides in Southern California Mud washes away personal belongings in the Sun Valley neighborhood of Los Angeles on January 9, 2018. Hide Caption 17 of 18 Photos: Deadly mudslides in Southern California Rushing rainwater fills the Los Angeles River near downtown Los Angeles. Hide Caption 18 of 18

The cleanup effort is arduous. Santa Barbara District Attorney Joyce Dudley said in a statement Sunday those who "encumber the continuing rescue efforts by unnecessarily entering the affected areas" could face fines and even jail.

She noted that the area is west of Sheffield Drive/East Valley Road/Ladera Lane, east of Olive Mill/Hot Springs Road, north of the ocean, and south of the US Forest Service boundary.

A Cal Fire search and rescue crew at a storm-damaged home in Montecito.

"Those areas are not only active search areas, but also remain dangerous. Therefore, unauthorized persons who enter those areas will not only interfere with critical and time-urgent search and rescue efforts, but may also become victims themselves."

A portion of US 101 -- a major freeway connecting Northern and Southern California -- will remain closed for at least another week through Montecito because of ongoing clean-up and repairs, and rain in the weekend forecast, according to the California Department of Transportation.