US-backed Kurdish forces tightened the noose Tuesday around ISIS fighters hunkering down inside a Syrian prison, with both sides facing a bloodbath or talks to end the five-day-old standoff.
Around 100 ISIS fighters attacked Ghwayran prison in the northeastern city of Hasakeh on January 20, in their biggest military operation since their military defeat in 2019.
The ensuing clashes with the Kurdish forces running northeastern Syria have left more than 160 people dead, including 45 in Kurdish ranks, according to the group Syrian Observatory for Human Rights.
Some of the estimated 3,500 IS prisoners inside the facility have already been bused out to other detention centers in recent hours but it was unclear how many remained inside Ghwayran.
Some of the hundreds of minors detained in the prison were transferred on Monday, the Observatory said.
"Kurdish forces are working on Tuesday to tighten the noose around ISIS members holed up in the northern part of the prison, while conducting careful search operations inside the buildings," Observatory head Rami Abdel Rahman told AFP.
"If there is no deal for a swap, there will be a massacre, hundreds of people will be killed," he said.
The Syrian Democratic Forces, the Kurdish administration's de-facto army, have not confirmed reports that several prison guards were being held by ISIS fighters.
The SDF said that 250 ISIS detainees had surrendered on Tuesday, bringing the total number of extremists who have turned themselves in to 550.
The Kurdish-led force's spokesman, Farhad Shami, insisted there were no ISIS fighters on the loose and that inmates who had broken out of their cells were contained within the compound perimeter.
SDF forces operating with air support from US-led coalition forces operating in the region have deployed elite units and armored vehicles in and around the converted school that became one of the world's largest ISIS prisons.
An assault has looked imminent since Monday but the Observatory said Kurdish forces were reluctant to move in due to the presence of hostages inside.
The SDF is counting on the besieged fighters running out of ammunition and supplies, Abdel Rahman said.
He said talks were taking place for some of the Kurdish troops and prison staff trapped inside to be freed in exchange for medical treatment for wounded extremist fighters.
ISIS fighters are holding about 27 hostages in the northern section of the prison, Abdel Rahman said.
Since Monday, 15 prison staff who were held by unarmed extremists have been released, according to the observatory. The fate of 25 others is still unknown.
Abdel Rahman said that while foreign ISIS members were thought to oppose a negotiated settlement, many of the Syrians among the inmates favored swap talks.
SDF spokesman Shami said that those among the inmates who wanted to surrender were being pressured by the most extremist ISIS members inside the prison.
"ISIS executed more than seven members of the organization who were terrorist inmates who wanted to surrender," he told AFP.
As bodies were still being retrieved from the scene of the battle and after sporadic clashes overnight, the death toll for the spectacular jailbreak attempt rose to 166.
The Observatory said 114 of the dead were affiliated with ISIS, while seven were civilians caught in the crossfire.
The United Nations said up to 45,000 Hasakeh residents were forced to leave their homes as the fighting raged and Kurdish forces locked down large parts of the city.
Most of the inmates in Ghwayran were captured by US-backed forces in late 2018 and early 2019, during the dying days of the terror group's self-proclaimed caliphate.
'I'm very scared'
The Save The Children charity said it had received audio messages from one Australian teenager who was taken to Syria at the age of 11 by his parents and called for help from inside the prison.
"There's no doctors here that can help me," he can be heard saying, after explaining he suffered injuries to his head and his hand during the fighting.
"I'm very scared, there's a lot of people dead in front of me," he also said in the recording, the authenticity of which AFP could not independently verify.
The proto-state declared by ISIS in 2014 once straddled large parts of Iraq and Syria.
After five years of military operations conducted by local and international forces, its last rump was eventually flushed out on the banks of the Euphrates in eastern Syria in March 2019.
An estimated 12,000 suspected ISIS members are still held in Kurdish prisons nearly three years on.