The Islamic State terrorist group has claimed responsibility for the attack outside a Prophet Mohammed cartoon contest in Texas and warned that in the future, far worse attacks will be carried out against "the nation of the cross."
On Sunday, two Muslim-Americans identified as Elton Simpson and Nadir Soofi opened fire outside the event in a Dallas suburb and succeeded in wounding a security guard before police shot and killed them.
In the broadcast aired on its official radio station Al Bayan on Tuesday, an ISIS radio announcer referred to Simpson and Soofi as the terror group's "brothers" and said the attacks were in retaliation for the contest, which it argued "portrayed negative images of the Prophet Muhammad." The message ended with an ominous warning to the United States:
"We say to the defenders of the cross, the U.S., that future attacks are going to be harsher and worse," the announcer said, CNN reports. "The Islamic State soldiers will inflict harm on you with the grace of God. The future is just around the corner."
Despite ISIS' claims, however, experts say there is no immediate indication that the jihadist group had contact with Simpson or Soofi, who both lived in Phoenix.
"Normally, it is sufficient for a person to say they are affiliated with ISIS even if they haven't been trained by ISIS, as it is in keeping with ISIS' call for people to carry out attacks on the west," Aymenn Jawad al-Tamimi, a researcher at the Interdisciplinary Center in Herzliya, Israel, told the New York Times. "It is not as if ISIS has a cell in the United States or trains people. This is not ISIS coming to America."
While U.S. authorities are currently investigating whether Sunday's shooting had any link to international terrorism, it has been confirmed that at least one of the shooters was influenced by jihadist thought. Moments before the attack, Simpson posted a tweet saying he and his fellow attacker had pledged allegiance to "Amirul Mu'mineen," which means "the leader of the faithful," and is believed to be a direct reference to ISIS leader Abu Bakr al-Baghdadi. The tweet ended with the hashtag #texasattack: "May Allah accept us as mujahideen."
A short time earlier, Simpson had asked his followers on Twitter to follow an ISIS propagandist. CNN reports that after the shooting, the propagandist tweeted: "Allahu Akbar!!!! 2 of our brothers just opened fire."
Simpson was also sentenced to three years probation back in 2011 after making a false statement involving international and domestic terrorism. At the time, he told FBI agents he had not discussed traveling to Somalia to engage in "violent jihad" -- when, in fact, he had.
The controversial Prophet Muhammad cartoon contest was hosted by political blogger Pamela Geller, who is president of the American Freedom Defense Initiative and author of The Post-American Presidency: The Obama Administration's War on America. The event was reportedly held in response to the Islamic "Stand With The Prophet" conference held at the same Texas location several months ago that featured New York-based Imam Siraj Wahhaj, who was an alleged "co-conspirator" in the 1993 World Trade Center bombings.
Geller's event included a $10,000 prize contest depicting caricatures of Muhammad and featured a keynote speech by Dutch politician Geert Wilders who is on an al-Qaeda hit list due to his film "Fitna."
"I am shocked. I just spoke for half an hour about the cartoons, Islam and freedom of speech and I had just left the premises," Wilder told the AFP in an email. "This is an attack on the liberties of all of us! I hope it is not connected to death list (of) al-Qaeda."
Speaking on Monday, Geller reacted to the shooting by telling Fox News, "Clearly what happened is indicative of how very vital this conference was needed. The idea that there is a violent war; there is a violent assault on freedom of speech, clearly was brought home last night...We will not abridge our freedom of speech in order to not offend savages."
Sunday's attacks come less than four months after a deadly shooting at a satirical newspaper in Paris that left 12 people dead. The newspaper, Charlie Hebdo, had previously been threatened by extremists for its caricatures of Muhammad and other sketches that are known to offend Muslims.