RIGHT SPEAK: ISIS in America: Claims Responsibility for Texas Attack

The gunmen: Elton Simpson, left, and Nadir Soofi

The Islamic State claimed responsibility Tuesday for the attack outside a Texas art show showcasing cartoon depictions of the prophet Mohammed, but it was not clear how much involvement the group actually had.

A statement read on the group's Al Bayan radio station said that "two soldiers of the caliphate" carried out Sunday's attack, the jihadist monitoring service SITE Intel Group said.

The bodies of the two men that drove up and starting
shooting at a security guard at the Muhammad Art
Exhibit and Contest at the Curtis Culwell Center are
removed from the crime scene in Garland, Texas.

If true, the attack would mark the first time the Islamic State has claimed responsibility for an attack on U.S. soil. It was not clear Tuesday if Islamic State leaders had any knowledge of the attack before it took place Sunday night at the Mohammed Art Exhibit event in Garland.

White House spokesman Josh Earnest said officials don't know if the Islamic State's claim of responsibility for the attack in Garland, Texas, is legitimate.

All that mayhem over this

"This is still under investigation" by the FBI and other agencies, Earnest said. "It's too early to say at this point."

Earnest also praised law enforcement officers for their efforts to "foil what appears to be an attempted terrorist attack."

The statement from Islamic State, also known as ISIS or ISIL, said: "We tell … America that what is coming will be more grievous and more bitter and you will see from the soldiers of the Caliphate what will harm you, God willing," the Associated Press reported.