The report described the footage as "horrific" and explains the mob was "unleashing [a] savage beat down."

Be aware of offensive language:

The report said the victims explained they were walking along the beach over the Memorial Day weekend before the attack.

"Frightening video posted online showed two victims curled up in the fetal position on the ground as the crowd continued to kick them, hurling profanities and racial slurs. A third Marine was also attacked but not shown in the footage," the report said.

Minor injuries were reported.

Eventually, two unidentified people passing by told the teens to back off, and deputies from Orange County soon arrived.

An investigation was underway and the teens, if identified, could face felony charges of assault with a deadly weapon.

The attack apparently started when a male teen was seen punching one of the Marines in the back of the head. An all-out brawl followed and the teens shortly circled the Marines, cursing them and kicking them.

Antonio explained the Marines were taking rare time off from Camp Pendleton, and he asked the teens to leave when they were setting off fireworks and a piece of debris hit him in the face.

"They were being belligerent and obnoxious and annoying other people, so I went up to them and told them to stop," he said, according to the report.

San Clemente Mayor Chris Duncan said, "This is San Clemente, Marines are always welcome here, always going to be celebrated, always taken care of, and that is why this is so particularly tragic."

The sheriff's office said patrol checks in the area have been increased.