Two men are dead after opening fire on a security guard outside an art event in Garland, Texas.

The New York Times reports that the shooting took place at 7 p.m. last night outside the Curtis Culwell Center, where the First Annual Muhammad Art Exhibit and Contest organized by the American Freedom Defense Initiative (AFDI) took place. The event featured a contest awarding a $10,000 prize to the best caricature of the Prophet Muhammad.

According to local authorities, the two assailants shot a security guard and were subsequently shot and killed by police officers. The names of the gunmen have not been released. The security guard, who was shot in the ankle, was taken to the hospital and has since been released.

“As today’s Muhammad Art Exhibit event at the Curtis Culwell Center was coming to an end,” the city of Garland confirmed via Facebook, “two males drove up to the front of the building in a car. Both males were armed and began shooting at a Garland I.S.D. security officer.”

Authorities immediately locked down the center following the attack, evacuating the nearly 200 participants from the event. A bomb squad was also called in after reports of a possible incendiary device at the scene.

Police spokesman Joe Harn told Reuters that the bodies of the two men were still lying in the parking lot hours later. “I have no idea who they are, other than they’re dead and in the street,” he said.

In a live video stream from the event, a security guard dressed in military fatigues bounds onto the stage to announce that there has been a shooting outside. A man in the crowd asks if the suspects are Muslim, to which the guard replies, “I have no idea right now.”

Depicting Muhammad is forbidden in Islamic culture, and while no official motives for the shooting have been released, this clash is reminiscent of the shooting at French satirical magazine Charlie Hebdo, a publication known for printing potentially offensive cartoons of Muhammad.

Garland Mayor Douglas Athas said the city had permitted the event even though officials knew its inflammatory theme could provoke an attack. “There was concern, which is why we had heightened security in the area, but we all swear to uphold the Constitution, free speech, free assembly and in this case perhaps, free religion,” he told Reuters.

The event was the brainchild of AFDI president Pamela Geller, who has been called the “anti-Muslim movement’s most visible and flamboyant figurehead… relentlessly shrill and coarse in her broad-based denunciations of Islam,” by the Southern Poverty Law Center.

The AFDI issued a statement via Facebook following the attack, stating: “This is war on free speech. What are we going to do? Are we going to surrender to these monsters?”