The operation began without warning: Aid groups were barred from the Syrian displacement camp, Internet signal disappeared, and soldiers fanned out along the chain-linked fences as a scorching sun rose high in the sky.

Inside, the women grew distressed. Some cried, some shouted abuse, and all were wary. They had once lived inside the Islamic State’s self-proclaimed caliphate. Now they were guarded by the force that defeated it, and tensions between the two were running high.

The operation this month to count and register the inhabitants of the al-Hol camp annex was described by aid workers, officials, researchers and families in touch with the women affected.

On June 10, the U.S.-backed Autonomous Administration of North and East Syria said that it had begun registering the foreign inhabitants of what it called “the most dangerous camp in the world,” almost a year and a half after they first arrived.

The Islamic State’s once-vast territory in Iraq and Syria is no more. But the question of what will happen to tens of thousands of foreigners who left for the caliphate and never returned home still lingers, with no clear answers.

Abandoned by their governments and under the care of a Kurdish-led force that does not want them, the women and children inside the al-Hol camp annex are among nearly 14,000 foreigners from more than 60 countries being held in northeastern Syria due to suspected Islamic State links. Some 30,000 Iraqis live in a separate, larger section of the camp. Inside the annex, some women still fly the Islamic State flag and impose its disciplinary measures.

Their futures were initially seen as a test of how their home nations would balance human rights responsibilities with security concerns. But as the months have worn on, their cases have slipped from the global political agenda. This month’s registration attempt, analysts say, appeared in part to be an attempt to streamline the camp’s administration by creating a comprehensive accounting of who actually lives there.

It could also be used to increase pressure on home governments to act.

The Kurdish-led authority in northern Syria says it cannot manage the task alone and has repeatedly appealed for action from foreign governments, citing a rising tide of attacks from Islamic State sleeper cells across the region.

Some countries, including the United States, have begun the repatriation process. But much of Western Europe has delayed, as officials cite security concerns or domestic politics as obstacles.

Inside al-Hol, one of a half dozen displacement and refugee camps in northeast Syria for families from Islamic State-controlled areas, the women’s tents are pitched on cracked earth that turns to mud when the rain comes. Latrines overflow, sewage leaks into tents, and wild dogs prowl the perimeter for food.

Dozens of women have disappeared from the camp, according to residents. Some leave with smugglers who charge as much as tens of thousands of dollars to take them away. Some, residents say, have ended up in makeshift detention facilities already holding thousands of foreign men in legal limbo.

Vera Mironova, a research fellow at Harvard University, maintains contact with scores of women inside the camp.

“A lot of people escape, and when they escape we don’t see any trace of them,” she said. “As long as governments don’t take their citizens back, or actually track them, these women can disappear into thin air.”

On the morning of June 10, aid groups operating in the annex were informed that they would not be able to enter for a two-week period during the registrations. The groups said they were also told the families would receive only bread and water during that time frame.

Women inside the camp have repeatedly accused the facility’s Kurdish-led authorities of withholding aid as a form of punishment. Humanitarian workers say that they sometimes struggle to operate inside the annex and that some workers have been attacked by the women.

In a video filmed earlier this month, shared by Mironova and reviewed by The Washington Post, a woman in a full black face and body covering addresses the camera as a water truck trundles away in the background.

“Drove by,” she says in Russian. “Didn’t stop. Didn’t pour water. Still waiting.”

As the camp was sealed off for the registration drive, guards led the women off in groups, according to family members of the women, humanitarian organizations and researchers. Australian and Canadian nationals were registered using biometric systems provided by the U.S.-led coalition. Some Russian speakers were recorded, too.

“Some of these women are still active ISIS members who need to be identified and removed from the civilian setting,” said U.S. Army Col. Myles B. Caggins III, a spokesman for the coalition. He said the information was to be added to an electronic database used by international law enforcement and intelligence officials.

The Kurdish-led administration did not respond to requests for comment. The coalition said 2,900 biometric tests and 8,000 DNA samples were collected. Their immediate use was not clear.

Family members and human rights groups say questions over the women’s role with the Islamic State should be determined in court, not presumed. They also say thousands of children across the camps have been traumatized from years of war, with scant access to education.

In al-Hol, children are everywhere. Many have lost fathers to the war or prison. Some sit alone in what shade they can find. Laughter is rare. Small boys play with homemade toy guns, appearing to replicate the body language of fighters they saw defending the Islamic State.

“Countries need to accept responsibility for their own nationals present in these detention facilities in Syria,” said Dareen Khalifa, a senior analyst at the International Crisis Group. “They should urgently repatriate vulnerable children and investigate the possibility of returning whole family units.”

In interviews with Washington Post reporters visiting al-Hol last year, dozens of women described a hardcore contingent who were seeking to replicate the caliphate’s brutal rule.

They argued that their own stories were complex. Some said they had traveled to the caliphate in the belief it would be a perfect Islamic State, but grew disillusioned by its brutality and were unable to escape. Some said they had arrived as teenagers and were not able to understand the gravity of their decision. Others said they had been coerced to join by abusive partners.

It was not possible to independently verify their accounts.

The women worried about their children’s futures. “There’s no life here, you know,” said a Dutch woman who identified herself as Bint Fatma, a nickname. She said she had told her 5-year-old son that they would probably be separated by authorities upon return to the Netherlands. “I need to prepare him,” she said.

The International Committee of the Red Cross on Friday urged countries to prioritize their child nationals. France last week announced the return of 10 children; officials said they were handed over to judicial authorities and were now in the care of social services.

“No matter the crimes their parents may have committed,” Khalifa said, “children who are in makeshift camps in northeastern Syria are innocent victims of the conflict.”

Loveluck reported from London. Isabelle Khurshudyan in Moscow and Alice Martins in al-Hol, Syria, contributed this report.