CAMP TARIQ, Iraq - As Iraqi security forces tighten their grip on the outskirts of militant-held Fallujah allegations of human rights violations are surfacing on both sides of the operation.
The U.N. human rights chief also cited "extremely distressing, credible reports" that Iraqis fleeing Fallujah are facing physical abuse and even cases of summary executions as they escape the city held by Islamic State of Iraq and Syria (ISIS) militants.
On Monday, hundreds of civilians, many bearing marks of torture were released north of Fallujah after being detained by a group of government sanctioned mostly Shiite militias. Five of those detained died while in the group's custody according to Yahya al-Muhamadi, an Anbar council member working with displaced civilians.
Zeid Ra'ad al-Hussein on Tuesday cited witness accounts that armed groups backing Iraqi security forces have detained some men and teenage boys leaving Fallujah with force that at times "degenerates" into abuse. Zeid acknowledged that Iraqi forces have a "legitimate interest in vetting individuals fleeing" ISIS-controlled areas to make sure they don't pose a security risk, but said official authorities should do so.
He said those fleeing must be presumed to be civilians, barring "clear and cogent evidence to the contrary." He urged the Iraqi government to take steps to ensure the protection of civilians.
The militia forces, known as the Popular Mobilization Forces, are one of a number of different Iraqi security forces participating in the operation to retake Fallujah ISIS, which has controlled it for more than two years.
The Popular Mobilization Forces deny that their fighters detain civilians.
"We are not authorized to detain anyone, we are just helping to move displaced people," said Hayder Mayahii, an official with the PMF's media office based outside Fallujah. Mayahii said his office was aware of the reports, but said they were completely false and the product of media bias.
The Popular Mobilization Forces illegally detained 605 people, al-Muhamadi the Anbar councilman said. "They tortured many of them, five people died from the torture."
Al-Muhamadi spoke as he oversaw the registration of hundreds of newly displaced civilians along the main road to the east of Fallujah. Late Monday night a dozen mini busses were packed with tired families from Saqlawiya and other neighborhoods north of Fallujah recently retaken from ISIS by Iraqi forces.
Local and federal Iraqi police regularly detain men and teenage boys from territory retaken from ISIS. The practice is part of a legal screening process to prevent ISIS fighters from escaping among the civilians, al-Muhamadi said.
In the row of mini buses on the road east of Fallujah, every family had been separated from all their male relatives over the age of 15. Iraqi security officials completing the registration process say the screening should only take three to five days and families will be quickly reunited.
But Amnesty International, a human rights organization says even civilians detained through the formal screening process are often held indefinitely without charge. Tens of thousands of civilians are estimated to still be in the custody of Iraqi security forces following the string of recent anti-ISIS territorial victories in Anbar province beginning in December of last year.
Inside the center of Fallujah, ISIS fighters are holding some 50,000 civilians captive and reportedly shot at a group of civilians attempting to flee the city Sunday across the Euphrates river, according to an international aid organization and the Iraqi military.
The operation to retake Fallujah from ISIS was launched in May. Iraq's elite counterterrorism troops began their push into the city center last week and secured the southern edge of Fallujah Sunday.
While Iraqi government officials have encouraged civilians still in Fallujah to flee, ISIS has threatened anyone who attempts to do so with death.
A mass grave has also been uncovered in Saqlawiya, a neighborhood north of Fallujah recently retaken from ISIS, according to the media arm of the Popular Mobilization Forces and the Iraqi military. Hanoon with the counterterrorism forces said an estimated 400 bodies, mostly Iraqi soldiers executed by ISIS, are believed to be in the burial site.