SAN CLEMENTE, Calif. — A woman killed herself and three other family members, including two young children, in what may have started as a child custody dispute in an upscale, gated Orange County community, authorities said today.

Sheriff’s deputies checking on the tenants were sent to a house in the Careyes community shortly before 2 p.m. Monday. They found the bodies of a 38-year-old woman and her daughters, ages 2 and 4, along with a close relative who was in her 60s, said sheriff’s spokesman Jim Amormino.

The four had been staying temporarily with a friend who was leasing the home, Amormino said.

He said that man was inside the home when a disturbance began.

“It raised a red flag,” Amormino said.

Concerned about the welfare of the children, he left and reported the disturbance to authorities at about 1:45 p.m., Amormino said.

Deputies were sent to check on the welfare of the children and found the bodies in a first-floor hallway of the red-roofed, mustard-colored stucco house. Nobody else was in the house.

The cause of death was not immediately released but it “was a very bloody scene,” and it appeared that one of the women killed the others and then herself, Amormino said.

Investigators were still piecing together what happened, but one motive being examined was a child custody dispute, Amormino said.

“There was a custody battle going on between the mother of the little girls” and the father, Amormino said. However, the father was not considered a suspect, he said.

The couple was divorced and he was not at the home.

No previous problems were reported at the home, Amormino said.

The deaths jolted the community, which has 42 luxury houses overlooking a golf course. The homes, with four to six bedrooms, sell for more than $1 million.

“It’s very shocking,” said next-door neighbor Rebecca Vandehei, who lit a stick of incense on her property in memory of the children.

“I did a prayer…I wanted to try to help,” she said.

“This is an upscale community,” Amormino said. “Crime is very low here.”

However, the last homicide report in town also involved a family massacre. Relatives who hadn’t heard from relatives broke into a home in another gated community in May 2008 and found five decomposing bodies.

Authorities said Margrit Ucar, 48, shot her husband and herself, while their 21-year-old twin daughters and the family’s 72-year-old maternal grandmother died from prescription drug overdoses in an apparent suicide pact. The motive has not been determined.

San Clemente, with about 65,000 residents, lies near the ocean about halfway between Los Angeles and San Diego. Spanish-style mansions and exclusive neighborhoods dot its hills. One home bought by then-President Richard Nixon in the late 1960s was nicknamed the “Western White House.” It was the Nixons’ vacation home and he hosted several world leaders there.