Nearly 5,700 Suspected ISIS Detainees Transferred to Iraq Face Imminent Prosecution, Human Rights Watch Says

Human Rights Watch warned Monday that nearly 5,700 alleged ISIS-linked men and boys transferred from northeast Syria to Iraq earlier this year now face imminent prosecution in Iraq, where adults could receive death sentences, as they are held in overcrowded conditions marked by disease concerns, abuse allegations and yearslong failures by dozens of countries to take back their nationals.

In a report published Oct. 5, the rights group said its findings were based on 56 interviews with family members, lawyers, officials, U.N. representatives, rights defenders and experts, as well as documents and correspondence. Iraqi judicial authorities told Human Rights Watch that terrorism trials are expected to begin in the coming days after interrogations of the detainees were completed.

The detainees were moved from northeast Syria to Iraq between Jan. 21 and Feb. 12 in an operation led by the U.S. military after fighting destabilized detention sites run by the U.S.-backed, Kurdish-led Syrian Democratic Forces. U.S. Central Command said U.S. and coalition forces “led mission planning, coordination, and execution” of the transfer.

Iraqi judicial authorities put the number transferred at 5,704. They said the group includes nationals of 67 countries, including 3,497 Syrians and 474 Iraqis; the remainder are from 65 other countries. Separately, six French nationals transferred earlier from Syria are scheduled to be prosecuted starting Oct. 5.

Human Rights Watch said the detainees are being held at Al-Karkh Central Prison near Baghdad airport, where, citing Iraqi prison authority sources, it said cells were operating at 158% capacity. The group also cited Iraqi and other sources as saying more than 1,100 adults arrived with serious and contagious illnesses, including tuberculosis.

HRW further reported, citing sources including an Iraqi prison authority, that one man died during the transfer and 14 others died after arrival, apparently from serious health conditions. Those death figures were reported by Human Rights Watch and were not independently confirmed in the brief.

The report said more than 440 of the detainees are children, including one as young as 12. An Iraqi judicial official told HRW that 305 of those children are believed to be Syrian. The group also said as many as 1,000 others are young men who were originally captured as boys and have been held ever since.

Adults are expected to be prosecuted under Iraq’s 2005 Anti-Terrorism Law, which allows for the death penalty. Human Rights Watch said many of the detainees had already been held in northeast Syria for as long as seven and a half years and that foreign detainees there had not been charged or prosecuted, making their detention arbitrary and unlawful under international law.

The group also said it received information that five foreign detainees alleged they were tortured during interrogations in Iraq in 2026, and it cited abuse allegations by 13 French detainees transferred in 2025. Iraqi judicial and prison authorities denied mistreatment, and Human Rights Watch said it could not independently confirm the torture allegations. Human rights groups have repeatedly criticized Iraqi terrorism trials in ISIS cases over due process concerns, including allegations of coerced confessions and rushed proceedings.

The transfers took place after prison breaks and broader chaos in northeast Syria raised fears about the security of detention facilities there. Since ISIS lost its territorial hold in 2019, tens of thousands of suspected members and family members had remained in prisons and camps in the region.

Human Rights Watch said most governments whose nationals are now in Iraqi custody have stalled or refused repatriation. It said only two detainees, both children, were known to have been repatriated by April 2026.

Iraqi officials told the group they need more outside help identifying detainees and investigating cases because many arrived without case files or identification papers. Ali Diaa, administrative director of Iraq’s National Center for International Judicial Cooperation, said: “We are looking for tangible support, not workshops and conferences.”

Letta Tayler, Human Rights Watch’s senior counterterrorism adviser, said the detainees and victims alike were owed a process that is both lawful and credible. “The thousands of boys and men sent to Iraq deserve humane treatment and due process, just as the thousands of survivors of ISIS crimes deserve genuine justice,” she said. “The international community shouldn’t leave Iraq to manage this immense responsibility on its own.”