Hundreds of suspected Daesh members swept up by Iraqi forces in Mosul are being held in a cramped and stifling prison just outside the city.
In one facility, more than 100 prisoners have been packed into a dark room, lined up shoulder to shoulder on the floor, without electricity or ventilation, despite daytime temperatures of well over 45 degrees Celsius.
The Iraqi officer who oversees the facility said it currently holds some 370 prisoners.
He said authorities were overwhelmed with detainees as Iraqi forces cleared the last neighbourhoods of the city earlier this month at the end of a gruelling nine-month campaign.
"Prisoners are infected with diseases, lots of health and skin problems because they're not exposed to the sun," he said.
The officer spoke on condition of anonymity because he was not authorised to brief the media.
"The majority can't walk. Their legs are swollen because they can't move," he said, adding that a provincial health team checks on the prisoners "occasionally."
More than 1,150 detainees have passed through the prison over the past three months, with 540 sent to Baghdad for further investigation, the officer said.
Another 2,800 prisoners are being held in the Qayara air base south of Mosul, and hundreds more in a few, smaller facilities.
Daesh seized Mosul when it swept across northern and central Iraq in the summer of 2014.
As US-backed Iraqi forces battled block by block to retake the city, many fighters also fled the city by hiding among fleeing residents, complicating efforts by Iraqi forces to separate the militants from civilians.
Prisoners say they're innocent
Prisoners who were discreetly interviewed insisted they were innocent. They spoke on condition of anonymity, fearing reprisals.
"You won't find 10 real (Daesh members) among these guys. And all of them have spent more than six months here," one prisoner said out of earshot of the guards. "Since I got here eight months ago, I've only seen the sun once."
He said he was a civil servant and had travelled between Baghdad and Mosul on several previous occasions before being detained.
"They said my name was in their database. I haven't seen any court or judge. I don't even know what I'm accused of. A lot of names are the same," he said.
He said two prisoners had died in the packed holding cell. Some prisoners "have pus coming out of their wounds. Once they go to the hospital, they come back with amputated legs or arms."
"We really want to die," another prisoner said. "None of us have received any visitors, relatives, family members. They don't even know where we are."
Military victories are fuelling extrajudicial killings of suspected Daesh members at the hands of Iraqi security forces.
Videos that emerged last week showed troops in Mosul taking captured Daesh suspects and throwing them one by one off a high wall next to the Tigris River, then shooting at their bodies below.
Four Iraqi officers from three different branches of the military and security forces openly admitted that their troops killed unarmed and captured Daesh suspects.
They spoke on condition of anonymity because they acknowledged such practices were against the international law, but all those interviewed said they believed the fight against Daesh should be exempt from such rules of war because the militant rule in Iraq was so cruel.
The killings risk tipping Iraq back into the cycles of violence that have plagued the country for over a decade, according to Belkis Wille, Iraq researcher with Human Rights Watch (HRW).
Daesh was able to attract recruits in the past because of people's anger over abuses, including arbitrary detentions, torture and extrajudicial killings, she said.
If abuses continue, "all you're going to see is (that) young Sunni Arab men are going to want to join whatever the next extremist group looks like," she said. Despite the military's vows not to tolerate it, she said no soldier or commander has been held accountable for any killings.
Last week, HRW urged Iraqi authorities not to punish entire families of Daesh militants "because of their relatives' actions" and that the abusive acts amount to "war crimes" after security forces "forcibly" relocated at least 170 families of alleged Daesh members to a closed "rehabilitation camp" which HRW said is a form of "collective punishment."