A teenage girl kidnapped in Texas was rescued in Southern California when passersby saw her hold up a handwritten “help me” sign in a parked car, police said.

The rescue of the girl, 13, occurred on July 9 in Long Beach, south of Los Angeles, when officers responded to a call and found the “visibly emotional and distressed girl”, police said.

“Through their investigation, officers learned the Good Samaritans were in a parking lot when they saw the victim in a parked vehicle holding up a piece of paper with ‘help me’ written on it. They acknowledged the note and immediately called 911,” police said.

Steven Robert Sablan, 61, of Cleburne, Texas, was arrested and on Thursday was indicted by a federal grand jury on charges of kidnapping and transportation of a minor with intent to engage in criminal sexual activity, according to the US attorney’s office in Los Angeles.

Sablan was being held at the federal Metropolitan Detention Centre in Los Angeles.

Police said the victim had been near a bus stop in San Antonio, Texas, on July 6 when the suspect approached in a vehicle, pointed a gun at her and demanded that she get in.

Detectives determined that the girl was sexually assaulted while being brought to California, and they found a replica firearm in the vehicle, the press release said.

The girl was placed in the custody of the Los Angeles County Department of Children and Family Services.

The FBI subsequently took charge of the investigation.