Homeland Security Secretary Jeh Johnson stated again Thursday that the four foreigners who were apprehended and questioned after crossing the U.S.-Mexico border did not have ties to terrorism.

Rather, they were members of the Kurdish Workers' Party (PKK), a group that is fighting ISIS, claimed Johnson.

"In September the public heard a claim that four individuals with suspected ties to terrorism in the Middle East had attempted to cross our southern border," Johnson said at an event at the Center for Strategic and International Studies (CSIS), according to CBS.

"Far fewer know that, in fact, these four individuals were arrested, their supposed link to terrorism was thoroughly investigated and checked, and in the end amounted to a claim by the individuals themselves that they were members of the Kurdish Workers' Party - an organization that is actually fighting against ISIL and defended Kurdish territory in Iraq. Nevertheless, these individuals have been arrested for unlawful entry, they are detained, and they will be deported."

Johnson was first publicly questioned on the border crossing by Rep. Jason Chaffetz, R-Utah, at a Homeland Security Committee hearing on Sept. 17, when Chaffetz asked if Johnson was aware that four individuals connected to "known terrorist organizations in the Middle East" were apprehended trying to cross the Texas-Mexico border.

"I've heard reports to that effect," Johnson replied. "I don't know the accuracy of the reports or how much credence to give them, but I've heard reports to that effect."

Chaffetz conducted an interview with CBS News after Johnson's comments, and stood by his assertions that four members of a terrorist organization were in fact caught crossing the border, citing State Department documentation that labels PKK as a terrorist organization.

"I don't think that should be dismissed as insignificant. It does demonstrate how porous our border is. These are terrorists nonetheless and they had no trouble crossing our southern border. That's a problem that must be addressed," Chaffetz said, proposing the question, "why aren't we prosecuting them, why are we simply deporting them?"

Rep. Duncan Hunter, R-Calif., said Tuesday on Fox News that Border Patrol told him that "at least 10 ISIS fighters have been caught coming across the border in Texas." A Department of Homeland Security spokesperson denied the claims.