SAN DIEGO -- American children who may have been mistreated in rehabilitative boarding schools in Baja California , Mexico, were escorted back into the United States this past weekend, 10News reported.

About 530 students from Casa by the Sea, located outside Ensenada, crossed into the U.S., as did 20 from Casa La Esperanza in Ensenada and other children from Genesis, south of Rosarito Beach.

Behavior modification programs offered at the schools reportedly were developed for children with drug dependencies and behavior problems. Parents reportedly turned to the schools as a last resort.

Authorities raided the schools after receiving reports that the youths were being mistreated.

Most of the children were initially sent to the Town and Country Hotel in Mission Valley where their parents were able to pick them up.

Former Casa by the Sea student Ryan Calburn said he wasn't surprised about the raid. He spent four months there.

"When I was there, some guy got slammed against the wall," Calburn said.

He also said he remembered routinely being forced to sit still for hours as discipline.

Many of the parents who came to pick up their children after the raid said they don't understand.

"He's only gone straight up since he's gone into this program," a parent said.

"It's so frustrating he's come so far, then upheaval, he was on track," another parent said.

Casa by the Sea school officials were not available for comment Sunday.