The attack by the Daesh terrorist group on a Syrian prison holding around 3,000 of its fighters and about 700 children is a predictable tragedy that spotlights the need for urgent international action to deal with those allegedly linked to the extremist group in prisons and camps in the country’s northeast, the United Nations counterterrorism chief said Thursday.

Undersecretary-General Vladimir Voronkov told the U.N. Security Council that the terrorist group "has been highlighting and calling for jail breaks," and "there have been previous instances in Syria and elsewhere in the world."

Most of the men, women and children with alleged links to Daesh who are held in Syrian prisons and camps "have never been charged with a crime, yet remain in prolonged detention, uncertain of their fate," the head of the U.N. Office of Counter-Terrorism said.

"It is a reminder also of why Daesh continues to embed itself in Syria."

Secretary-General Antonio Guterres has warned that the threat from Daesh is growing, including in Syria where Voronkov said it is organized in small cells "hiding in desert and rural areas, while they move across the border between Iraq and Syria to avoid capture."

The latest incident at the Gweiran Prison, also known as al-Sinaa, located in the northeastern city of Hassakeh, is the biggest by Daesh militants since the fall of the group’s "caliphate" that once spanned significant parts of Syria and neighboring Iraq in 2019.

Voronkov said the fighting also affected the civilian population and resulted in the escape of an unknown number of fighters for the Daesh.

United States-backed YPG forces, which is the Syrian branch of the PKK terrorist group, said Wednesday they had taken control of the last section of the prison controlled by Daesh militants and freed a number of child detainees they said had been used as human shields, but Voronkov said the fighting was "ongoing."

The counterterrorism chief said he was "appalled" by reports that children, who should never have been held in military detention, were used as human shields. "Although the group’s barbarism should come as no surprise, these children have been left prey to be used and abused in this way," he said.

Voronkov reiterated his call for countries to repatriate alleged Daesh fighters and their families in prisons and camps in northeastern Syria.

"The repatriation of third-country nationals from Syria and Iraq remains a major priority for the United Nations and we stand ready as a reliable partner to member states in responding to these challenges," he said. "Daesh’s attempts to break its fighters freed from prison underlines the need to bring them to justice as soon as possible, and ensure accountability to break the cycle of violence."

U.N. special envoy for Syria Geir Pedersen told the Security Council on Wednesday that the Daesh prison attack "brings back terrible memories of the prison breaks that fueled the original rise of ISIL in 2014 and 2015," using another acronym for Daesh.

"I see this as a clear message to use all of the importance of uniting to combat the threat of internationally-proscribed terrorist groups – and to resolve the broader conflict in which terrorism inevitably thrives," Pedersen said.

Russia called for the briefing on the prison attack and its deputy ambassador, Dmitry Polyansky, accused the United States of saying it abides by international humanitarian law which calls for the protection of civilians in armed conflicts but using its air force and armored vehicles to clear the prison of Daesh fighters.

He said the United States ignored "measures to protect civilians" at the prison and elsewhere, including U.S. airstrikes in Baghouz, Syria in March 2019 that he said killed at least 80 civilians.

Polyansky also accused the U.S. of illegally occupying Syria’s northeast and "looting oil."

U.S. deputy ambassador Richard Mills countered, accusing Russia of turning the council meeting "into a rhetoric-driven mass of disinformation and – frankly – lies about the U.S. role in Syria." He said American forces are in the northeast as part of a coalition "for the sole purpose of continuing the fight" against Daesh extremists.

Northern Syria's different parts are controlled by the Russia-backed Bashar Assad regime, U.S.-backed YPG terrorists and Turkey-backed opposition groups.

The PKK is a designated terrorist organization in the U.S., Turkey and the European Union, and Washington's support for its Syrian affiliate has been a major strain on bilateral relations with Ankara. The U.S. primarily partnered with the YPG in northeastern Syria in its fight against the Daesh terrorist group. On the other hand, Turkey strongly opposed the YPG's presence in northern Syria. Ankara has long objected to the U.S.' support for the YPG, a group that poses a threat to Turkey and that terrorizes local people, destroying their homes and forcing them to flee.

Under the pretext of fighting Daesh, the U.S. has provided military training and given truckloads of military support to the YPG, despite its NATO ally's security concerns. Underlining that one cannot support one terrorist group to defeat another, Turkey conducted its own counterterrorism operations, over the course of which it has managed to remove a significant number of terrorists from the region.