Multiple U.S. officials say the FBI is investigating more than a dozen migrants from Uzbekistan and other countries allowed into the U.S. after they sought asylum at the southern border with Mexico earlier this year.

U.S. intelligence officials found that the migrants traveled with a smuggler with ISIS ties, according to a report by CNN.

National Security Council spokesperson Adrienne Watson said the FBI is still trying to “identify and assess” all immigrants, even if no ISIS plan has been found. According to two U.S. officials, they are closely examining many migrants as criminal dangers.

Though there was reportedly insufficient evidence to detain anyone, the situation was sufficiently disturbing that President Joe Biden's senior Cabinet members received an urgent secret intelligence report in their daily briefing book.

It illustrates that the U.S. is vulnerable to terrorists sheltering along the southern border amid the influx of asylum seekers, according to some counterterrorism authorities.

The incident sparked a flurry of urgent talks with top national security and administration officials as Republicans pound Biden on southern border security ahead of the 2024 campaign.

A group of Uzbek migrants requested asylum and were examined by the Department of Homeland Security earlier this year, joining a growing number of Central Asian asylum seekers in the U.S.

The people were let into the U.S. pending a court date since none of the intelligence community's databases aroused any red flags.

National security authorities finally put the pieces together when the FBI discovered a human smuggling network aiding foreign nationals come to the U.S. that included at least one ISIS member.

FBI agents everywhere promptly sought out the migrants and investigated their histories.

U.S. officials said the agency collaborated with Turkish authorities, who detained the smuggler and other members of his network at the U.S.'s request and got information from him to help its probe.

“There was no indication—and remains no indication—that any of the individuals facilitated by this network have a connection to a foreign terrorist organization or are engaged in plotting a terrorist attack in the United States,” Watson said in a statement to CNN.

Since the intelligence became available, Homeland Security officials have also begun detaining, verifying, and expediting the removal of other migrants encountered at the southern border who "fit the profile associated with individuals who were facilitated by this network," Watson said.

U.S. officials have stated they believe the smuggler with ties to ISIS is not a member of the terrorist organization but rather an independent contractor with personal sympathies for the group.