ISIS Claims Failed Attack on Texas Art Show that Killed 2 Gunmen

The Islamic State militant group claimed it was behind the attack on a cartoon exhibition of the Islamic Prophet Mohammad in Texas on Sunday in which two of its alleged fighters were killed.

However, U.S. officials expressed doubts on the ISIS' direct involvement in the attack even as investigators continued to look for clues on the botched terrorist attack.

Wielding assault rifles, Elton Simpson and Nadir Soofi of Phoenix were gunned down by a police officer when they opened fire in a parking lot outside the Muhammad Art Exhibit and Cartoon Contest in Garland, a suburb of Texas. An unarmed security guard suffered a minor wound.

The Syria- and Iraq-based ISIS said on its official online radio station that "two soldiers of the caliphate" launched Sunday's attack in Dallas.

The White House said it was not yet clear whether the two gunmen killed in Garland had ISIS links. Investigators said they were still trying to determine whether the slain gunmen had received orders from ISIS before carrying out the attack.

According to one U.S. official, investigators believed it was possible, if not likely, that ISIS played an "inspirational" rather than "operational" role in the attack.

Even before the Muhammad art exhibit was held, the police in Texas were already prepared for any possible attack.

The extra police security paid off as the two gunmen were killed before they could inflict harm on more people.

The contest was organized by the American Freedom Defense Initiative, which has been tagged by the Southern Poverty Law Center as an anti-Muslim group. The organizers reportedly paid $10,000 for extra security.

According to the Garland police, the event was coming to an end when Simpson and Soofi drove up to the front of the Curtis Culwell Center facility armed with assault weapons and started shooting at a Garland security officer.

The police engaged the gunmen, killing both.

The security officer, Bruce Joiner, sustained a wound to his ankle and was released after treatment.

Police suspected that the car used by the suspects had explosives and detonated several packages inside it. But no explosive devices were found.

Simpson, according to CNN, linked himself to ISIS in a tweet before the attack. "May Allah accept us as mujahideen," according to the tweet.

The Simpson family said in a statement late Monday it was at a loss to explain what happened. "We are heartbroken and in a state of deep shock as we grieve," the family statement said. "We send our prayers to everyone affected by this act of senseless violence, especially the security guard who was injured in the line of duty."

Court documents showed Simpson had been under U.S. surveillance since 2006 and was convicted in 2011 of lying to F.B.I. agents about his desire to join jihad in Somalia.

"I believe that perhaps he might have just snapped when he heard about the cartoon contest," Kristina Sitton, a Phoenix attorney who defended him in the case, told CNN.

Soofi, the other slain gunman, was described by his friends as a popular student at an elite school in Pakistan. However, they said he had difficulty adjusting to life in the U.S. after his family left Pakistan and settled in the U.S.

Homeland Security Secretary Jeh Johnson said, "While all the facts are not in yet, last night's attack serves as a reminder that free and protected speech, no matter how offensive to some, never justifies violence of any sort."

"Finally, in reaction to last night's attack, we urge that members of the public not misdirect anger and suspicion at people simply because of their religious faith," he said.

The Council on American-Islamic Relations (CAIR) condemned the Sunday's attack.

"We also reiterate our view that violence in response to anti-Islam programs like the one in Garland is more insulting to our faith than any cartoon, however defamatory. Bigoted speech can never be an excuse for violence," the council said.

The shooting in Texas resembled attacks or threats in other Western countries against the display of images depicting the Prophet Mohammad.

In January, gunmen killed 12 people in the Paris office of French satirical magazine Charlie Hebdo after it printed a caricature of Mohammad in its cover. Such portrayals are considered offensive by Muslims.