Four of nine teenage boys, missing from a ranch for troubled youths in southern New Mexico under investigation for alleged abuse, are safely back with their families, police said on Saturday.
They said Amber Alerts, issued in cases of child abductions, would remain for the other five missing boys.
A lawyer for the ranch has said all of the boys were safely with their parents on a "previously scheduled activity away from the ranch for several days," but police could not yet confirm their safety.
New Mexico State Police on Friday issued an Amber Alert for the nine teens aged 13 to 17 after they went to the Tierra Blanca Ranch near Deming, New Mexico, to investigate following reports that boys were beaten, shackled for days and denied food as punishment.
The establishment came under increased scrutiny last month after one of the teenagers, Bruce Stager, 18, was killed when he was thrown from the back of a pickup truck.
Authorities said they went to the ranch on Friday with a search warrant and court orders requiring operator Scott Chandler to turn over the nine boys to the Children Youth and Families Department, but found no one there.
It is not clear how the boys returned to their families and police said the alerts on the five boys would remain until they could confirm their safety.
"And even though other parents of the missing boys have made contact with state officials, the Amber Alert will remain active until an official can confirm their location and individual well-being," police said in a statement.
New Mexico Governor Susana Martinez on Friday said the state had received allegations of abuse at the ranch and that it was required to investigate.
"Law enforcement and child social workers did show up with court orders to interview the children and to interview anyone else who was at the residence," Martinez said in the Friday news conference. "There was no one there."
Police said they consider Chandler a person of interest in the investigation and have asked him and the parents of the other boys to contact state police.
The program, which operates on a 30,000-acre (12,000-hectare) cattle ranch, offers "a new beginning for troubled and at-risk youth," according to its website.
An attorney for the program, Pete Domenici Jr., and Tierra Blanca Ranch could not be reached for comment on Saturday.
(Reporting by Noreen O'Donnell and Kevin Murphy; Editing by David Bailey and Sandra Maler)