LONDON -- The Islamic State extremist group has sought to link itself to Sunday's attack in Garland, Texas, during which two assailants shot a security guard before being killed by police officers outside an event devoted to cartoons depicting the Prophet Muhammad, a group that monitors extremist activity online reported Tuesday.
The Islamic State, which is waging an insurgency in Syria and Iraq, said on its official radio station Al Bayan that "two soldiers from the soldiers of the caliphate" had carried out the attack, according to the SITE Intelligence Group, which quoted the extremists as saying that the two soldiers attacked an exhibit "holding a contest for drawings offensive to the Prophet Muhammad."
In its statement Tuesday, the Islamic State was quoted by SITE as saying future attacks on Americans would be "worse and more bitter, and you will see from the soldiers of the Islamic State what will hurt you, Allah permitting."
The statement provided few details, however, and it remained unclear whether the extremist group was involved even indirectly in the attack or whether it was making the claim purely for propaganda value.
White House spokesman Josh Earnest said it's too early to say whether the Islamic State played a role in the assault. He said U.S. officials are working aggressively to counter terrorist efforts to use social media to radicalize individuals in the United States.
The group has shown pattern of trying to attract recruits by praising terrorist attacks against Western targets for which it may have provided ideological inspiration rather than weapons or training, officials said.
Although the Islamic State is seen as well-organized in the territory in Iraq and Syria where it has declared a caliphate, or Islamic state, there is little evidence that the group, which is sometimes known as ISIS or ISIL, has actively planned or directed attacks abroad.
"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," said Aymenn Jawad al-Tamimi, a researcher at the Interdisciplinary Center in Herzliya, Israel, who studies the Islamic State. "It is not as if ISIS has a cell in the United States or trains people. This is not ISIS coming to America."
In voice recordings released online, Islamic State leaders have called on their followers to attack "infidels" wherever they may be, by running them over with cars, stabbing them or throwing them off cliffs. Most attacks associated with the group outside of Islamic State territory appear to have been planned and executed at the local level with little more than inspiration provided by the organization, officials have said.
The little information publicly available about the attackers in Texas suggests that they had been influenced by different currents of jihadist thought. A Twitter account believed to be associated with the gunmen used a profile picture of Anwar al-Awlaki, a Yemeni-American cleric who had been with al-Qaida before he was killed in an American drone strike in Yemen in 2011.
But a post from the same account pledged fealty to Abu Bakr al-Baghdadi, the head of the Islamic State, which has broken with al-Qaida and competes with it for prestige and recruits.
American law enforcement officials are still trying to piece together whether others were behind the attack that was carried out by two men, Elton Simpson, 30, and Nadir Hamid Soofi, 34, in Garland, a suburb of Dallas. The authorities have started to examine the backgrounds of the two men, who lived in the same apartment complex in Phoenix.
One has been identified by the FBI as a jihadist terrorism suspect who regularly attended a mosque in Phoenix. The other ran a carpet cleaning business and also attended a mosque.
Authorities have not revealed whether Simpson and Soofi had any contact with the Islamic State.
The event at which the attack took place included a contest for the best caricature of Muhammad, with a top prize of $10,000.
The Texas attack bore some resemblance to January's attack by Islamic extremists on the offices in Paris of the satirical newspaper Charlie Hebdo, during which 12 people were killed after the newspaper published cartoons lampooning Muhammad. In the Texas shooting, only the gunmen were killed.
The Charlie Hebdo attack was followed by others in and around Paris, during which Amedy Coulibaly, a French citizen of African descent, killed four people at a kosher supermarket before he was shot to death by the police.
A video made before the attack later surfaced in which Coulibaly declared his allegiance to the Islamic State, described his role in what he called a coordinated attack to defend Islam, and urged young people to take up the fight.
However, the extent of direct involvement by the Islamic State in the Paris attacks has not been determined. Lone-wolf individuals can declare allegiance to an extremist group such as the Islamic State, and extremist groups can exploit attacks for their propaganda value.
In the case of the Paris attacks, the two brothers who attacked Charlie Hebdo said they were followers of a rival militant group, al-Qaida's branch in Yemen, known as al-Qaida in the Arabian Peninsula. Both extremist groups praised those behind the Paris attacks.
The organizers of the event in Texas said they held the event as a celebration of free speech. Pamela Geller, a blogger who organized the event, has said Muslims are being singled out as a special group about whom American values of freedom of speech are not being applied.
However, pro-Muslim advocates, while strongly criticizing the violence, have denounced what they see as a provocation that offended many Muslims. In most interpretations of Islam, cartoons or visual representations of Muhammad are considered blasphemous.
In Sunday's attack, Simpson and Soofi were wearing body armor, and one of the men shot a security officer in the leg before a single Garland police officer fired on the two gunmen. After his initial shots, nearby SWAT officers also fired.
The security officer was treated at a hospital and released.
Simpson was previously arrested in 2010 after being the focus of a four-year terror investigation. But despite amassing more than 1,500 hours of recorded conversations, including Simpson's discussions about fighting nonbelievers for Allah and plans to link up with "brothers" in Somalia, the government prosecuted him on only one minor charge -- lying to a federal agent.
Federal prosecutors said he had aimed to go to engage in violent jihad, but a judge ruled that the government had not been able to prove that part of the charge. He was sentenced to three years of probation.
Simpson had worshipped at the Islamic Community Center of Phoenix for about a decade, but he quit showing up over the past two or three months, the president of the mosque said.
The center's president, Usama Shami, said Simpson would play basketball with mosque members and was involved with the community. Soofi owned a nearby pizza business and would stop in to pray occasionally, he said.
"They didn't show any signs of radicalization," Shami said.
Sharon Soofi, the mother of Soofi, told The Dallas Morning News that her son may have somehow snapped.
"The hard thing to comprehend is why he would do this and leave an 8-year-old son behind," said his mother, who now lives in a small town southwest of Houston.
In a statement released late Monday by Phoenix law firm Osborn Maledon, Simpson's family said it is "struggling to understand" what happened.
"We are sure many people in this country are curious to know if we had any idea of Elton's plans," the statement said. "To that we say, without question, we did not."
Information for this article was contributed by Dan Bilefsky and Ben Hubbard of The New York Times and by Julie Watson, Ryan Van Velzer, Eric Tucker, Nancy Benac, Brian Skoloff, Paul Davenport and Jamie Stengle of The Associated Press.
A Section on 05/06/2015