As many as 50 migrants remain at large after an ISIS-linked smuggling operation brings hundreds to the US, according to DHS.

Over 400 individuals have been brought to the U.S. from Eastern European and Central Asian countries by an ISIS-affiliated smuggling network in the past several months, a DHS senior official confirmed to Planet Chronicle on Wednesday.

Over 150 individuals have been arrested and either removed, placed in removal proceedings, or are undergoing additional screening. Officials refused to confirm if or how many of them match the terror watchlist. Out of the remaining 50 individuals, a small number may be on the terrorism watch list.

The official stated that there is no evidence to suggest that the remaining individuals pose an immediate danger to the homeland.

The officials stated that only a small number of the 400 individuals are considered "subjects of concern," while the majority are not. This determination was made after one of the organizers was found to have ties to an Islamic terror group, prompting the need for precautionary measures to identify, apprehend, and screen all individuals associated with the network.

At a press conference in Arizona on Wednesday, Homeland Security Secretary Alejandro Mayorkas stated that it was "inaccurate" to claim that 400 migrants with possible links to ISIS had been transported to the U.S.

""It is crucial to be precise when dealing with facts, especially when it comes to identifying individuals with potential ISIS ties," he emphasized."

Weeks after eight Tajikistan nationals with ties to ISIS were arrested in New York City, Los Angeles, and Philadelphia, the latest revelations about the network were reported by NBC News. Despite coming in via the southern border illegally, no derogatory information was flagged during processing.

DHS does not consider this an ISIS terror operation, but rather a group exploiting migrants trying to enter the U.S. Nevertheless, there is a heightened security risk due to their countries of origin. As a result, border officials have been instructed to detain individuals from specific countries or linked to the network for additional vetting.

DHS has been closely examining migrants from Central Asia due to concerns raised by recent terror attacks in Russia by ISIS and its affiliates, as reported by NBC.

Officials have acknowledged that it is challenging to vet migrants when they arrive with no information, as Acting ICE Director Patrick Lechleitner recently stated that "sometimes there is just no information on individuals" during the vetting process.

"Where there is nothing, individuals do not have anything. There are no criminal convictions, threat information, or anything else on these people. Perhaps they are from a particularly concerning area, but that information may surface later," he stated.

The Special Operations Association of America (SOAA) sent a letter on Tuesday expressing its members' grave concerns about the terrorist threat to the United States and Americans abroad.

The letter asserts that our complete withdrawal from Afghanistan has resulted in a vacuum in the region, allowing anti-American terrorist groups such as al-Qaeda and the Islamic State to flourish once again due to the lack of a viable stay-behind or over-the-horizon counterterrorism and intelligence capability to suppress threats.

The absence of intelligence gathering in the region poses a threat to the United States.

The "unsecured southern border" is exacerbating the terrorist threat, as stated in the letter. We cannot determine the number of terrorists currently within the U.S.

The latest chorus of warnings about the terrorist threat comes from a letter written by former national security officials.

"Former CIA acting Director Michael Morell stated on CBS' "Face The Nation" Sunday that there is a lack of a sense of urgency and the American people need to understand the threat."

The Biden administration was immediately blamed by Republicans for the smuggling network revelations at the southern border.

"Rep. August Pfluger, R-Texas, chairman of the House Homeland Security Subcommittee on Counterterrorism, stated that he is a former U.S. Air Force fighter pilot who fought ISIS in Syria and Iraq. He expressed his concern that the Biden administration has opened the border, allowing terrorists to smuggle illegal aliens into the country. He vowed to take immediate action from the administration and work with his colleagues to address any security gaps, emphasizing the safety of the nation as his top priority."

Planet Chronicle’ Lucas Tomlinson and Bill Melugin contributed to this report.