SAN DIEGO -- The Marine Corps is investigating two active-duty Marines at Camp Pendleton for a social media post of a photo of a corporal in uniform holding an assault rifle and the message: "Coming to a gay bar near you!"

Maj. Staci Reidinger said Thursday that fellow Marines alerted officials to the post, and authorities were able to track down the Marine in the photograph and another one who reposted it.

According to the Marine Corps Times, the post appeared on a private Facebook group for male Marines with the words "Too soon?" before the administrator deleted it and banned the person from the group.

"We believe that it was a very insensitive and possibly dangerous photo that needed to be taken seriously given the nature of the possible threat," the administrator, Michael Moss, said in an email.

Moss said the group has 25,000 members and receives about 3,000 posts a week.

"We rely on our members, who are comprised of all active duty and veteran service members, to help moderate, which they did," Moss wrote. "As a group, we do not condone any type of hate speech or threats."

Reidinger said the posting goes against Marine Corps values.

"This is a very serious incident and we see this as potential misconduct based on the fact in the picture is a US Marine and the person who reposted the picture also is a US Marine," she said. "This goes against good order and discipline within the Marine Corps and the Marine Corps has a very high standard of not tolerating discrimination against any type of group."

She added that fellow Marines policed their own by immediately reporting the post.

"It's an embarrassment to us," Reidinger said of the post.

The post follows Sunday's terror attack on a gay nightclub in Orlando, Florida, that killed 49 people and injured more than 50.