WASHINGTON — A year after United States-backed forces seized the last remnant of territory under Islamic State group rule in Syria, some 10,000 captured Islamic State fighters in Kurdish-run wartime prisons pose “a significant risk” to the U.S. mission in the country’s northeast, military commanders say.

Hardened Islamic State fighters protesting the dire conditions in their makeshift confines, including the potential spread of COVID-19, have rioted at the largest prison in Hasaka twice in the past two months. The uprisings were quelled, but they underscore the “high-impact risk of a mass breakout,” U.S. commanders told investigators from the Pentagon inspector general’s office.

These findings, contained in the inspector general’s latest quarterly report on the U.S. military missions in Iraq and Syria, issued earlier this month, represent new and alarming warnings for a U.S. counterterrorism mission that already faces renewed attacks from resurgent Islamic State guerrillas, pressure from Russian troops supporting the army of President Bashar Assad of Syria, and concerns that the coronavirus could infect their own ranks.

These concerns have limited operations of the 500 remaining U.S. troops in northeastern Syria.

Only a handful of COVID-19 deaths have been reported in the country’s northeast, and none so far in the prisons. But humanitarian assistance workers express fear that a rapid outbreak is a real possibility given the region’s war-battered health infrastructure and the severe overcrowding at its prisons.

“The humanitarian situation in places of detention and in camps in Syria’s northeast was dire even before the threat of COVID-19 appeared,” said Fabrizio Carboni, the Near and Middle East director for the International Committee of the Red Cross. “We’re extremely worried about all detainees during this pandemic.”


Carboni added: “Their living conditions make them extremely vulnerable should the virus enter and spread. We know that overcrowded, unhygienic and poorly ventilated cells create the perfect conditions for that to happen.”

The Syrian Democratic Forces, whose fighters are the Pentagon’s partner on the ground in the yearslong campaign against the Islamic State, operate a constellation of about two dozen ad hoc detention sites for captive Islamic State fighters, including converted schoolhouses and a former Syrian government prison at Hasaka, the site of the recent riots.

The prisons hold about 10,000 men, of whom about 8,000 are locals — Syrians or Iraqis — and about 2,000 are from 50 other nations whose home governments have balked at repatriating them. Scores of those men are Europeans, from countries like Belgium, Britain, France and Germany, but far more come from across the Middle East, including Egypt, Tunisia and Yemen.

Many European law enforcement officials fear that if they repatriate their extremist citizens, they would be unable to convict them or keep them locked up for a long time. Some countries have stripped suspected Islamic State fighters of their citizenship. The scant repatriations that have taken place over the past several months — including by Kazakhstan, Oman and Tunisia — stopped altogether given COVID-19 restrictions, U.S. officials said.

The Kurdish-led force that holds the Islamic State fighters does not have the capacity to investigate or try them, U.S. officials say. Western counterterrorism officials say the longer the foreign fighters are held, the more they become even further radicalized and the greater potential for mass breakouts.

The Kurds also operate more than a dozen camps for families displaced by the conflict that hold tens of thousands of people, many of them non-Syrian wives and children of Islamic State fighters. These include the sprawling al-Hol camp about 25 miles southeast of Hasaka, where some 70,000 people have been living in increasingly dire conditions.


Counterterrorism officials fear that these camps not only enable Islamic State communications and financial networks, but are also ideological breeding grounds for the next generation of extremists.

In the months following the Islamic State’s loss in March 2019 of its last remnant in northeast Syria, the village of Baghouz, U.S. and Kurdish officials said the Kurds could not sustain security long-term at the makeshift facilities it was using.

That became clear in October, when the Turkish military moved into northern Syria after getting a green light from President Donald Trump. Turkey targeted the U.S.-backed Kurds, calling into question the Kurds’ ability to secure the Islamic State fighters. About 100 fighters escaped in the turmoil, but Kurdish officials said they recaptured the majority of them.

Then came the riots at the prison in Hasaka, which holds between 4,000 and 5,000 captives. Media reports said that on March 29, Islamic State militants began breaking down doors and digging holes in walls between cells. The rioting was brought under control the next morning, but violence erupted again with gunfire heard inside and ambulances called in to help the wounded.

Five weeks later, in early May, Islamic State fighters briefly took control of the same prison. The riot ended a day later when Kurdish officials and members of the U.S.-led coalition negotiated with the militants.

“ISIS prisoners significantly outnumber the SDF guards, and the generally poor conditions in these jails are driving detainees to take greater risks to break out,” said Nicholas Heras, head of the Institute for the Study of War’s Middle East security program, using another term for the Islamic State group. “ISIS also has a long-standing policy to seek to break out its fighters from prison, which makes these SDF facilities a focus of ISIS efforts to replenish its ranks in Syria and Iraq.”


Gen. Kenneth F. McKenzie Jr., the head of the military’s Central Command, told Congress in March that the detention of foreign fighters and ongoing attempts at radicalization in the displacement camps were parts of the same problem.

U.S. and allied forces were helping to mitigate prison security risks by training and equipping Kurdish guards and helping construct more secure structures, McKenzie said. But he called those efforts “a tactical-level Band-Aid, not a long-term solution.”

The Pentagon has increased the amount it will spend to repair, renovate and, beginning this year, build new detention structures, up to $20 million from $10 million, with a $4 million cap on any single project. The pandemic delayed site-survey teams from visiting potential locations, but Pentagon officials said initial construction of new prisons could start in the coming months.

In addition, the Defense Department is paying the Syrian Democratic Forces between $500,000 and $1 million in stipends for guard salaries and other costs, according to Pentagon officials. Kurdish leaders have expressed appreciation for the aid, but echo McKenzie’s long-term assessment.

“Our allies must find a quick radical solution to this international problem,” Mazlum Abdi, the Kurdish force’s commander, said in a Twitter message after the first riot at the prison in Hasaka.