UPDATE Sexual Predator Threatens 2 with Knife: Boys Escape

UPDATE: Sheriff's investigators believe the two boys attacked in a park Sunday night in Ladera Ranch were the victims of armed robbery. Investigators no longer consider the incident an attempted sexual assault. Read more about the current investigation here.

A 12-year-old boy was threatened at knifepoint to remove his pants and underwear about 7:30 Sunday night inside Founders Park near Ladera Elementary School, said Orange County Sheriff's spokesman Jim Amormino.

The attacker has not been captured, he said.

Two boys, both 12, were playing on the park swing set when they were approached by a man with a 3- to 4-inch pocket knife, Amormino said.

He said one boy escaped to get help, while the other was dragged by the attacker about 10-15 feet.

The attacker ordered him to take off his pants, which the boy did. He then ordered the boy to remove his boxers. The boy threw wood chips into the kidnapper's face and ran away, Amormino said.

The boy flagged down a passing driver while still in his boxers. Deputies searched the area but found no one.

Detectives are checking with registered sex offenders in the area and sending information about the case to nearby law enforcement entities, Amormino said.

Amormino said the case does not sound similar to any recent incident in Orange County, but does resemble some similar cases in Los Angeles County.

He said the attacker is wanted for assault with a deadly weapon, child molestation and kidnapping.

"The victim was not sexually violated, but because of his age it's child molestation," he explained.

Investigators want to hear from anyone who saw a male Hispanic in his 20s wearing a blue hoodie, bandana and sandals in that area near that time. Anyone with information is encouraged to call 1-855-TIP-OCCS or 714-628-7170.