Eight Tajikistan nationals with suspected ties to the Islamic State were arrested across three U.S. cities in recent days. 

All eight men entered the U.S. illegally through the southern border and passed initial background checks, according to federal sources that told Fox News the men were “fully vetted.” But passing a background check often does not mean much, according to Thomas Homan, the former acting director of Immigration and Customs Enforcement under former President Donald Trump.

“Thousands of terrorists in the world are not found in any database,” Homan told The Daily Signal. “That is why we need to end catch and release and reestablish the ‘Remain in Mexico’ [policy].” 

Homan said he has been raising concerns about the vulnerability of the southern border for three years because the sheer numbers arriving at the southern border daily are preventing Border Patrol from conducting proper vetting of illegal aliens through deep dive interviews and other means. 

“Federal law requires that illegal aliens that enter the U.S. illegally ‘shall be detained,’” Homan said. “The Biden administration needs to stop ignoring the law, stop violating the law and secure our border. You will never have strong national security without strong border security.”

Former Border Patrol Chief Rodney Scott echoed Homan, telling The Daily Signal that border security “has always been fundamentally” about preventing illegal entry. 

“The entire purpose is to identify and prevent threats from ever entering our home,” Scott said. “The Biden administration soundly rejected this commonsense public safety principle in favor of a reactionary strategy that lets everyone into our home and then tries to sort out the threats afterwards. Now we are seeing the results.”  

The White House did not respond to The Daily Signal’s request for comment.

ICE worked with the FBI to make the arrests of the Tajikistan nationals in Los Angeles, New York, and Philadelphia, the New York Post’s Jennie Taer first reported. 

ICE arrested six of the men after the FBI flagged their suspected ties to the radical Islamic terrorist groups. The two other men in the group were apprehended following surveillance over the course of several months, according to NBC. 

A wiretap was a part of the investigation into the illegal aliens, which revealed one of the now apprehended men reportedly talking about bombs. 

The Department of Homeland Security and the FBI told the New York Post in a joint statement that the arrests were “carried out in close coordination with the FBI’s Joint Terrorism Task Forces. The individuals arrested are detained in ICE custody pending removal proceedings.” 

Between the beginning of fiscal year 2017 and end of fiscal year 2020, Border Patrol apprehended 11 individuals on America’s terrorist watch list between ports of entry at the southern border. Since the beginning of fiscal year 2021 to present, Border Patrol has apprehended 362 illegal aliens on the terror watchlist between ports at the southern border.