Army personnel have been cautioned on the risk of mass shooters when attending screenings of the movie “Joker.”

The Army confirmed Wednesday that a security notice was distributed internally after an FBI investigation unearthed social media posts associated with extremists classified as misogynistic “incels” that suggested replicating the 2012 movie theater shooting in Aurora, Colorado, during the Batman film “The Dark Knight Rises,” Gizmodo reported.

The notice, obtained by Gizmodo, said:

Team, Posts on social media have made reference to involuntary celibate (“incel”) extremists replicating the 2012 theatre shooting in Aurora, Colorado, at screenings of the Joker movie at nationwide theatres. This presents a potential risk to DOD personnel and family members, though there are no known specific credible threats to the opening of the Joker on 4 October. Incels are individuals who express frustration from perceived disadvantages to starting intimate relationships. Incel extremists idolize violent individuals like the Aurora movie theatre shooter. They also idolize the Joker character, the violent clown from the Batman series, admiring his depiction as a man who must pretend to be happy, but eventually fights back against his bullies. When entering theatres, identify two escape routes, remain aware of your surroundings, and remember the phrase “run, hide, fight.” Run if you can. If you’re stuck, hide (also referred to as “sheltering in place”), and stay quiet. If a shooter finds you, fight with whatever you can. ** this is a condensed version of an HQ Army Materiel Command, G-3, Protection Division Security message **

An Army spokesperson from the Criminal Investigation Command field office confirmed to HuffPost that a memorandum was sent out to a select internal group on Monday from the Fort Sill field office in Oklahoma after the information was obtained from the Joint Crime Information Center at the Texas Department of Public Safety.

The spokesperson said the CIC field office did so “out of an abundance of caution to help keep our soldiers and their families safe.”

The field office said it was not aware of any information indicating a specific, credible threat to a particular location or venue.

An FBI spokesperson told HuffPost that, although “our standard practice is to not comment on specific intelligence products, the FBI is in touch with our law enforcement and private sector partners about the online posts.”

“As always, we encourage the public to remain vigilant and to promptly report suspicious activity to law enforcement.”

The Oct. 4 release of the Warner Bros. film prompted family members of several Aurora shooting victims to write a letter to Warner Bros. CEO Ann Sarnoff expressing concerns about the Joker character being portrayed as a “protagonist with a sympathetic origin story” and asking the studio to donate to charities that aid victims of gun violence.

They described the shooter who killed their family members at the midnight screening of “The Dark Knight Rises” as a “socially isolated individual who felt ‘wronged’ by society.”

“Joker” writer-director Todd Phillips said in an interview with The Associated Press that it was unfair to link the movie to real-world violence, saying “it’s a fictional character in a fictional world that’s been around for 80 years.”

Warner Bros. extended its sympathy to shooting victims in a statement and said they had a long history of donating to victims of violence, including Aurora victims. They defended the film, saying they believed that “one of the functions of storytelling is to provoke difficult conversations around complex issues” and that the film’s intention was not to “hold this character up as a hero.”

This story has been updated with comment from the FBI.