The beating of a gay man outside a bar resulted in the arrest of four Camp Pendleton Marines and was being investigated as a potential hate crime, Marine Corps and police officials said Wednesday.

The beating occurred at around 2 a.m. Monday, Camp Pendleton spokesman Maj. Manuel J. Delarosa said. The Marines have since made bail and returned to their units.

Military officials were assisting Long Beach police, and the Marine Corps was also conducting its own probe and gathering "all of the details to ensure we have a full understanding of this incident," Delarosa said.

U-T San Diego quoted Long Beach police Cmdr. Joe Stilnovich as saying at least one of the suspects used derogatory terms regarding the victim's sexual orientation. He also told the newspaper that authorities were trying to determine each person's role in the assault.

Long Beach police spokeswoman Lisa Massacani said the victim was treated at a hospital for non-life-threatening injuries. Two others who tried to help the victim suffered minor injuries.

"This is an isolated incident," Delarosa said. "Committing any hate crime is unacceptable behavior and is not tolerated in the Marine Corps."

Neither Massacani nor Delarosa gave specifics on why it is being considered a possible hate crime.

Arrested were Lance Cpl. Lewis Serna; Pfc. Thomas Pentek; Pfc. Sean Miller and Lance Cpl. John O'Leary. The four Marines could not be reached for comment.