Los Angeles ? A mudslide swept over a Greek Orthodox youth camp Thursday, trapping up to 30 people as heavy rains triggered flooding in areas ravaged by wildfires last month, authorities said.

Nine to 12 of those victims were rescued from the Saint Sophia Camp in Waterman Canyon, just north of San Bernardino, authorities said. Two rescue teams were headed to the camp Thursday night in search of more people — one hiking up the canyon and the other hiking down because the road was washed out.

Authorities were not certain how many other people were trapped under mud and debris — if any. Victims said more people had been at the camp than had been rescued, but it was not known whether they had made it out on their own, San Bernardino County Sheriff’s Department spokeswoman Cindy Beavers said.

Up to 18 people could still be at the camp, said Sgt. Dave Caddel of the San Bernardino County Sheriff’s Department. Two cabins at the camp were destroyed, he said.

Authorities had no details about the people rescued, who were taken to area hospitals for treatment. Beavers said authorities were unaware of any serious injuries.

Boulders, logs, trees and branches, propelled by 1 to 3 inches of rain, tumbled down the San Bernardino Mountains, making rescue efforts treacherous and threatening homes and forcing road closures in several areas. Television reports showed a surging stream of water in Waterman Canyon, which looked like a sea of gray mud.

The mudslide occurred exactly two months after the start of a wildfire that ravaged much of the canyon, consuming just over 91,000 acres, destroying nearly 1,000 homes and killing four people.

Wildfires make Southern California’s mountains much more prone to mudslides because they burn off vegetation that normally would help shore up steep terrain. The fires that hit the region in October and November were the most severe in state history, burning nearly 1 million acres.

Authorities evacuated residents and closed off the road leading to the Waterman Canyon.

Flood waters became worse late Thursday, forcing officials to pull back some emergency personnel, county fire officials said. Caddel said sheriff’s search-and-rescue teams would continue to look for possible victims through the night.

A man begs a firefighter to search for his missing 4-year-old daughter as he is trapped under heavy boulders, mud and tree trunks from a torrent of mud and water that swept through a campground in Waterman Canyon, north of San Bernardino, Calif. A mudslide swept over a church youth camp Thursday, trapping at least 15 people as heavy rains triggered flooding in areas that were devastated by wildfires last month.