The Orange County Sheriff's Department reported that four boys and a female were booked into Orange County Juvenile Hall for assault with a deadly weapon (non-firearm). San Clemente Mayor Chris Duncan later told the Los Angeles Times four additional minors were arrested on other charges.
The melee began about 9:15 p.m. Friday near the pier at the end of Avenida del Mar, Orange County Sheriff's Department spokesman Mike Woodroof said.
The Marines were treated at the scene for minor injuries to their hands, knees, abdomens and heads, but declined to be taken to a hospital, Woodroof said.
It was unclear how many people attacked the men, but Woodroof said the number was likely somewhere between 10 and 30.
"The barbaric assault on off-duty Marines at the San Clemente Pier goes against everything we stand for in San Clemente, and it's no excuse that teenagers were involved," Duncan told The Times.
"I want to assure our community, especially our military and veteran community, that we take this matter with the utmost seriousness and will not tolerate this kind of behavior in our city. The fact that this incident occurred over Memorial Day weekend is particularly tragic."
Anyone with information regarding the beating, was asked to call the Orange County Sheriff's Department at 949-425-1956. Tipsters who choose to remain anonymous can call the Orange County Crime Stoppers at 855-TIP-OCCS.