The Department of Homeland Security has identified over 400 migrants who were brought to the US from Central Asia and other places by an ISIS-affiliated human smuggling network — and the whereabouts of more than 50 of them are unknown, according to an unsettling report.

More than 150 of the migrants have been arrested, but the locations of another 50 remain unknown, three US officials told NBC News, adding that US Immigration and Customs Enforcement is looking to arrest those involved on immigration charges.

Migrants from around the world continue to arrive across the US southern border, like these seen on June 10, 2024. James Breeden for the New York Post
An ICE agent monitors hundreds of asylum seekers in NYC. Getty Images

“In this case, it was the information that suggested a potential tie to ISIS because of some of the individuals involved in [smuggling migrants to the border] that led us to want to take extra care,”  a senior Biden administration official told the outlet, “and out of an abundance of caution make sure that we exercised our authority in the most expansive and appropriate way to mitigate risk because of this potential connection being made.”

The official noted that since ICE started arresting migrants brought into the US by the smuggling group several months ago, no information has tied them to any threats to the US.

Many of the over 400 migrants involved had crossed the southern border and were released into the country by Customs and Border Protection because they were not on the government’s terrorism watchlist, the three anonymous officials said.

While the agency did not have information raising concerns at the time the migrants entered the country, recent terrorist attacks in Russia have caused heightened concern over ISIS and its offshoot ISIS-K.

As a result, the Department of Homeland Security has been monitoring migrants coming from Tajikistan, Uzbekistan, Moldova, Kyrgyzstan, Georgia and Russia — all places ISIS-K has been observed.

Texas National Guard soldiers install border fencing layered with concertina wire near the Rio Grande River. Getty Images

One of those hotbed locations, Tajikistan, had over 1,500 migrants come into the US between October 2020 and May 2024, according to leaked border data obtained by The Post.

It’s unknown how many of the Tajik migrants were released into the US, but the vast majority of migrants caught at the border claim asylum and are allowed to stay while they await a court hearing.

ISIS-K was responsible for a massive attack on a concert hall in Moscow — carried out by citizens of Tajikistan — that killed 145 people and wounded hundreds more on March 22.

“The fact that the whereabouts were unknown is clearly alarming,” former FBI counterterrorism section chief Christopher O’Leary told NBC.

Customs and Border Patrol agents load migrants into a vehicle. AFP via Getty Images

According to O’Leary, ICE is likely looking to arrest these people even if there’s no evidence they are plotting a terrorist attack. 

“I believe the [U.S.] is scrambling to locate these individuals, and using the immigration charges is not uncommon,” O’Leary said. “They are in violation of that law. And if you need to take somebody off the street, that’s a good approach to do it.”

Federal law enforcement agencies are “not panicking” about the group of people, but they have been identified as “subjects of concern,” and are prioritizing them for arrest out an an abundance of caution, two of the officials noted. 

Some of the 150 migrants who were arrested have already been deported out of the country, the officials added. 

While some of those detained or deported have been charged with immigration violations, none have been charged with terrorism-related offenses. 

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