Terror group ISIS claimed on Tuesday that it is responsible for the attack on Sunday at a cartoon contest featuring images of the Muslim prophet Muhammad in Garland, Texas, and warned "the defenders of the cross" that more attacks on U.S. soil are to follow.
Fox News reported that the claim was made on ISIS' Al Bayan radio station, based in the Syrian city of Raqqa, which the terror group has established as its capital.
"We say to the defenders of the cross, the U.S., that future attacks are going to be harsher and worse. The Islamic State soldiers will inflict harm on you with the grace of God. The future is just around the corner," the terror group said in its message, according to CNN.
The Christian Post previously reported that Sunday's event was hosted by political blogger Pamela Geller, president of the American Freedom Defense Initiative, in response to the controversial Islamic "Stand with the prophet" conference held at the same Texas location on Jan. 18 that featured New York-based Imam Siraj Wahhaj, who was an alleged "co-conspirator" in the 1993 World Trade Center bombings.
January's "Stand with the prophet" Sunni Muslim conference, which Geller's event was held in response to, was a fundraiser to help "build a communication center for the Muslim community" to combat American media and "defend prophet Muhammad, his person, and his message in the U.S. where this anti-Islam hate machine is based," according to a post on the Sound Vision website, which has since been removed.
One of the suspects in the Texas attack was identified as Elton Simpson, a Muslim and U.S. citizen who was born at Dallas' Texas Health Presbyterian Hospital, and was once the subject of a terror inquiry, FBI officials said as they launched an investigation into the incident.
Texas officials have said that the suspects, Simpson alongside Nadir Soofi, drove up to the Curtis Culwell Events Center in the Dallas suburb of Garland where the "Muhammad Art Exhibit and Cartoon Contest" was being held, and opened fire. They wounded Bruce Joiner, an off-duty Garland police officer, was working the event as an unarmed security guard for the Garland Independent School District which owns the facility.
The Texas shooting is the first time ISIS has directly claimed responsibility for an attack on American soil, though it has warned of such intentions several times in the past.
ISIS, which clams to be a Sunni Muslim offshoot of al-Qaeda, has addressed Christians as the "nation of the cross" a number of times in its propaganda and beheading videos, such as in its execution of 21 Coptic Christians back in February, and a similar video where it killed 28 Ethiopian Christians in April.
Back in April, the Islamic militants, who have captured territory across Iraq and Syria and have moved into other countries such as Libya, warned in a video titled "We Will Burn America" that an "army of Jihad" is coming. They said that they are planing another 9/11-style attack, and told Americans that their country's geographical location will not bring them the safety they perceives to have.
In January, ISIS also threatened to behead President Barack Obama and turn America into a Muslim province.
In their latest message, the jihadists warned: "We tell America that what is coming is more bitter and harder and you will see from the soldiers of the Caliphate what harms you."
The Islamists claimed that the contest "was portraying negative images of the prophet Muhammad," as any image of Muhammad is considered blasphemy in the Islamic faith.
While U.S. authorities are investigating whether Simpson or Soofi, who both lived in Phoenix, had any links to international terrorism, they have not yet confirmed whether the suspects are indeed ISIS sympathizers.
Moments before the attack, however, Simpson posted a Tweet reading "May Allah accept us as mujahideen." The statement is a reference to ISIS leader Abu Bakr al Baghdadi, according to CNN terrorism analyst Paul Cruickshank.