When eight Tajik men sought asylum at the southwestern U.S. border a few months ago, federal authorities had no reason to suspect they were desperate migrants fleeing an impoverished, war-torn Central Asian country.
But shortly after they were allowed into the country, the FBI learned of their possible ties to the Islamic State and launched a counterterrorism investigation.
This was no ordinary investigation: Dozens of agents kept close watch on the men as they made their way to cities across the US, officials said, and the White House was regularly briefed on the situation.
The agency had hoped to gather intelligence on a broader terrorist network, but concerns grew over the possibility of an attack in at least one location, leading to the arrest of all eight men earlier this month on immigration charges, according to U.S. officials who spoke on condition of anonymity to discuss the classified investigation. So far, the men have not been charged with terrorism-related offenses.
The dramatic incident came amid growing anxiety among U.S. officials who have been warning for months that the conflict in Gaza and unrest in Central Asia could spill over into the United States, perhaps in the form of small militant groups or lone-wolf terrorists acting on their own.
New details about the FBI's investigation and decision to arrest the suspects underscore the flood of terrorism threats inundating national security agencies, some emanating from well-known international actors and others from emerging hotspots like Tajikistan.
Since the Oct. 7 Hamas attacks in Israel, the FBI has “received more than 1,800 reports of threats or other types of information or leads that are somehow related or connected to the current conflict between Israel and Gaza,” Deputy Attorney General Lisa Monaco said in a television interview in December. She added that many of the cases have been resolved without incident.
National security officials are deeply concerned by the speed with which the threat is evolving.
“Looking back on my career in law enforcement, it is difficult to think of a time when so many different threats to public safety and national security were elevated at one time, but that is certainly the case as I sit here today,” FBI Director Christopher A. Wray told Congress this month, days before the men were arrested.
An FBI spokesman declined to comment.
Republicans and conservative media have for years talked about the potential danger posed by terrorists who could cross into the United States from the southwest border along with tens of thousands of Latino immigrants. These fears have been largely unrealized.
It remains unclear whether the men were actually planning a terrorist attack, whether it was orchestrated by the Islamic State or inspired by other extremist groups, but the resources the FBI has devoted to the case underscore how seriously the bureau continues to take this threat as a top priority.
The arrests come at a time of heightened political attention on border security, an issue that has become a major bone of contention between President Biden and former President Donald J. Trump, who frequently spoke about “immigrant crime.”
Still, Rep. Jim Himes, a Connecticut Democrat and ranking member of the House Intelligence Committee, argued that the incident should be seen in context, warning that there are “zero deadly terrorist attacks committed by illegal immigrants across our southern border” and “zero Americans injured by foreign-born terrorists who entered the country illegally.”
Tajik followers of the Islamic State, particularly the affiliate known as ISIS-K, have played an increasingly visible role in several recent terrorist attacks. In the past year alone, Tajiks have been involved in attacks in Russia, Iran and Turkey, as well as thwarted plots in Europe.
ISIS-K, also known as the Islamic State of Khorasan Province, was formed in Afghanistan in 2015 by disgruntled members of the Pakistani Taliban, who have since embraced a more violent form of Islam. The group's numbers had dwindled to about 1,500 to 2,000 fighters by 2021, after many of its leaders were killed in U.S. airstrikes and Afghan special forces raids.
The group regained strength shortly after the Taliban overthrew the Afghan government that same year. During the withdrawal of U.S. troops from the country in August 2021, ISIS-K carried out a suicide bomb attack at Kabul's international airport, killing 13 U.S. soldiers and 170 civilians.
ISIS-K has since rekindled its global ambitions, with ethnic Tajiks making up more than half of its several thousand fighters, experts say.
While Russia is a frequent target, ISIS-K has also vowed to attack Americans and the United States.
Most details about the FBI investigation remain secret, but interviews with several US officials familiar with the case have provided new insights.
Officials said the men entered the US at the Southern California-Texas border sometime after 2023. They are all Tajik, but at least one held a Russian passport, and some of the men may have known each other.
They traveled to Los Angeles, Philadelphia and New York, areas with large Central Asian populations, and the FBI tracked them down, determining they might have ties to or sympathize with the Islamic State.
That set off a wide-ranging investigation reminiscent of the FBI's efforts after the Sept. 11 attacks, when it pursued several terrorism suspects for thwarted attacks, including a plot to attack the New York subway in 2009. In previous high-priority terrorism investigations, the FBI has relied on aerial surveillance and Section 702, its key warrantless surveillance program, to gather intelligence.
The program allows the government to collect communications from foreign nationals overseas who are targets of intelligence activities, even when those individuals are interacting with Americans.
For the FBI and Wray, the risk was enormous: If any of the suspects had escaped and carried out a terrorist attack, the FBI would have been blamed for not arresting them sooner, exposing itself to even greater criticism from Republicans. But there's always a trade-off: making an arrest makes it harder to gather intelligence on a possible network.
In the case of the Tajik attackers, officials said it remained unclear what they were up to, whether they were receiving instructions from terrorist groups outside the United States or were attempting to carry out the attack independently.
The FBI eventually learned about the men's actions, causing FBI counterterrorism officers to take them off the streets and arrest them on immigration charges. US Immigration and Customs Enforcement and FBI agents arrested the men, whose names have not been released, in New York, Los Angeles and Philadelphia over the weekend of June 8.
Federal authorities have not disclosed publicly What led investigators to believe the men may have terrorism ties? At the time, law enforcement officials would only say that they were arrested after unspecified “damaging information” was discovered about them.
In a separate lawsuit, lawyers representing a group of people from Uzbekistan filed a federal lawsuit against the U.S. government in February, alleging that migrants from the Central Asian country are being subject to detention at the southern border.
Officials said that if Tajiks are detained only on immigration suspicion and not on other federal crimes, they will almost certainly be deported.
In congressional testimony before his arrest, Wray alluded to the threats even as the FBI was quietly monitoring the suspects.
“But now we are increasingly concerned about the possibility of a coordinated domestic attack similar to the ISIS-K attack we saw at a Russian concert hall in March,” Wray said.
The attack near Moscow left more than 130 people dead and many of the suspects arrested were Tajiks.
Julian E. Barnes and Glenn Thrash Contributed report.
