The U.S. is hosting some 53,000 Afghan civilians across eight military bases, who were evacuated amid the chaotic American withdrawal.
The evacuees, many of them granted a special status called "humanitarian parole" while on base, are met with refugee resettlement services to streamline the immigration process.
Angela Fernandez is with the Department of Homeland Security:
"Our guests at Fort McCoy are currently completing immigration paperwork, including employment authorization and health screenings to prepare them for their resettlement in the United States."
But Reuters has learned that something strange is happening: Hundreds of Afghan evacuees are simply walking off the bases.
Two sources familiar with data said the number of "independent departures" top 700, and could be higher.
And these walk-offs are alarming immigration advocates worried new arrivals who abandon the resettlement services and the critical benefits offered could find themselves at the mercy of a complex U.S. immigration system down the road.
One U.S. Citizenship and Immigration Services official, who spoke on condition of anonymity, described it as "a giant can of worms," and warned, "this could lead to years and years of terrible immigration status problems."
In a statement, a U.S. Department of Homeland Security spokesperson declined to comment on the figures provided to Reuters. But DHS said people who had left the bases "generally" had ties to the United States, such as family members of friends, and resources to support themselves.
Immigration experts say Afghans who leave the bases are not breaking U.S. laws. Military officials have no legal authority to hold law-abiding Afghans against their will.
Some hard-line anti-immigration activists have raised concerns that the Afghan evacuees could pose a national security risk.
But U.S. officials stress that all of the Afghans leaving U.S. bases had already undergone security screening.
The risk of the independent departures is to the Afghans themselves.
Reuters viewed a document, entitled "Departee Information," that is meant to warn Afghans considering leaving before completing their resettlement. It reminds them that, on base, they can get their immigration paperwork processed and even cash to help pay for travel to their destination in the United States.
It reads, "once you leave this base, you forfeit these advantages and may not return."