For years, Al-Hawl and Al-Roj have been two big problems, with no easy solutions.
The detention camps in north-eastern Syria collectively housed more than 70,000 people at their peak in 2019.
They included the wives and children of Islamic State group fighters, who were captured or killed when US-backed Kurdish forces helped defeat the terrorist group.
After holding a large swathe of autonomous territory that included both camps, Kurdish-led forces are now reluctantly handing over control to Syrian government forces following their successful military offensive.
Syria seized the Al-Hawl camp in January, prompting many detainees to flee as the Kurds retreated.
For now, Al-Roj is still controlled by the Kurdish-led Syrian Democratic Forces (SDF) and its future is uncertain.
But after repeatedly asking foreign countries to repatriate their citizens, officials in Al-Roj have been letting detainees with travel documents leave.
It's an opportunity a group of 34 Australian women and children weren't about to pass up.
But their journey to Australia hit a roadblock, when Syrian authorities wouldn't let the group leave the Kurdish-held zone.
They appear to be caught in the middle of a power struggle that dates back many years.
Kurds help defeat Islamic State group
After controlling large parts of northern Syria and neighbouring Iraq, the Islamic State group was defeated in 2019, thanks to the joint efforts of Kurdish forces and a US-led coalition.
The Kurds went on to control nearly a third of Syria's territory, much of it rich in resources.
But in late 2024, Syrian president Bashar al-Assad's regime was toppled by Islamist rebels.
The new president, former fighter Ahmed al-Sharaa, vowed to unify the country, which had been gripped by more than a decade of civil war.
That included taking back territory held by the Kurdish-led SDF.
Syrian government launches lightning offensive
In January, Syrian government forces launched a major military offensive against the SDF.
Following days of violent clashes and significant territorial losses, the SDF agreed to a ceasefire.
Under the terms of the deal, Kurdish military and civil structures would be gradually absorbed into the central Syrian government.
Government forces would also be deployed to major Kurdish cities.
The US, which had long supported the SDF, had since established friendly terms with the government of Ahmed al-Sharaa, the rebel leader who has been ruling Syria since ousting Bashar al-Assad in 2024.
President Donald Trump even hosted al-Sharaa at the White House, in what was the first-ever visit for a Syrian leader.
Trump also rolled back sanctions and welcomed Syria into an anti-Islamic State coalition.
In January, as Syrian government forces consolidated power over Kurdish-held territory, the US suggested the SDF had passed its use-by date.
"The original purpose of the SDF as the primary anti-ISIS force on the ground has largely expired," US special envoy to Syria Tom Barrack said.
"Damascus is now both willing and positioned to take over security responsibilities, including control of Daesh detention facilities and camps," he said.
Syria signalled it planned to close both Al-Hawl and Al-Roj camps.
[Map of camps]Syrian forces take over Al-Hawl
Syrian government forces took control of the larger camp, Al-Hawl, after the SDF rapidly withdrew in January.
During the chaos, many of the foreign IS-linked families reportedly escaped, and aid agencies had to pull back due to security fears.
Before the SDF withdrew, more than 12,000 families lived in Al-Hawl and roughly half were foreigners.
There are now reportedly fewer than 1,000 families living there.
The Syrian government has transferred some families from Al-Hawl to a new camp near Aleppo, in the country's north-west, but many former detainees remain unaccounted for.
Before the ceasefire, SDF forces also withdrew from a prison housing IS militants, after coming under fire from Syrian government forces.
The SDF claimed at least 1,500 detainees escaped, but the Syrian government said only 120 broke free, and that most were recaptured.
Against that backdrop, this week the US said it had transferred 5,700 Islamic State prisoners to Iraq, saying it would prevent a resurgence of Islamic State in Syria.
While the SDF still controls Al-Roj — which is home to the Australian cohort — the camp's days could be numbered.
Its administrators are now trying to send home as many foreign detainees as possible, while it still has control.
A reluctance to repatriate
There are approximately 2,000 women and children living in Al-Roj.
Aid agencies have warned conditions in the camp are growing increasingly dangerous, with inadequate access to food, clean water and medical care.
While Australian officials have previously visited the Australians in Syria, the federal government is only offering limited assistance.
Temporary travel documents have been issued, allowing the 11 women and 23 children to leave Al-Roj.
But as they discovered on Monday, that's only half the battle.
One of the women is now subject to a temporary exclusion order (TEO), which could bar her from entering Australia for up to two years.
On Thursday, Prime Minister Anthony Albanese said he had "nothing but contempt" for the women who had travelled to Syria.
After leaving the camp and heading for Damascus, Syrian forces instructed the convoy to turn around, saying their journey from the Kurdish-held region had not been properly coordinated.
A source with high-level knowledge of Australia's national security protocols told the ABC it was possible Australia asked Syrian authorities to delay their passage while it scrambled to impose a Temporary Exclusion Order.
They said the prime minister's condemnation of the women was a distraction from the obligations Australia had to its citizens, however politically unpalatable they may be.
