Four Southern California police officers were arrested for allegedly abusing children at a boot camp organized in May by two police departments in San Luis Obispo County, authorities said Wednesday. Parents claimed that officers slapped, beat and kicked their children at the week-long camp.

Officers Marissa Larios and Patrick Nijland of the Huntington Park Police Department and officers Carlos Gomez-Marquez and Edgar Gomez of the South Gate Police Department were arrested Tuesday and Wednesday, San Luis Obispo County Sheriff's Department said, in a statement.

All four suspects were drill instructors at the Leadership Empowerment and Discipline program from May 17 through May 24. They posted a bond of $20,000 and were not in custody Wednesday, authorities said. The investigation was launched after the Los Angeles County Department of Children and Family Services sent a report of the allegations to the sheriff’s department on May 28. 

The officers were arrested for charges of willful cruelty to a child, criminal threats, abuse under color of authority (misdemeanor) and criminal battery (misdemeanor). All charges would be filed with the San Luis Obispo County District Attorney's Office, officials said.

Thirty-seven children attended the camp, of which 13 boys and girls -- aged between 12 and 17 -- claimed they were physically assaulted by the officers. Initially, seven children came forward with abuse claims, Greg Owen, a lawyer for the children’s families said, in June.

Sheriff's spokesman Tony Cipolla said that the injuries included "bruising to the face, bruised ribs, a lot of abrasions," according to the Associated Press. "I think generally roughed up would be a good description," he added. One boy reportedly suffered a fractured hand.

Araceli Pulido, who sent her daughters, aged 12 and 14, to the camp said one of her girls was "slapped in the face" and "kicked in the ribs if she didn't do her push-ups right” NBC Los Angeles reported.

“One of my oldest daughters said she wanted to become a cop," Pulido said, adding, "She's traumatized. They told her they got paid for her to get hit."

The mother of a 13-year-old boy reportedly said: "They had him by the neck with their forearm and they just beat in his head, stomach, everywhere."