The top U.N. human rights official called on Iraq on Tuesday to stop groups that are fighting alongside government forces against Islamic State from taking revenge on civilians and to clarify the fate of hundreds who went missing.
Witnesses say a Shi’ite militia that helped the army recapture Falluja from Islamic State in early June abducted more than 600 Sunni Muslim men and boys who had just fled the city.
The disappearances, along with one of the worst single bombings in Iraq to date in Baghdad on Saturday “increase the likelihood of a renewed cycle of full-throttle sectarian violence,” U.N. High Commissioner for Human Rights Zeid Ra’ad Al Hussein said in a statement.
Islamic State claimed responsibility for the attack late on Saturday in a busy shopping district. At least 175 people were killed.

Zeid said there was a list of 643 missing men and boys, as well as of 49 others believed to have been summarily executed or tortured to death while in the initial custody of Kata’ib Hezbollah, an Iranian-backed Shi’ite militia, after Falluja was re-taken. Tribal leaders believe another 200 are unaccounted for.
“This appears to be the worst – but far from the first – such incident involving unofficial militias fighting alongside Government forces against ISIL”,” Zeid said.
He noted that the government was investigating the disappearances and urged it to prevent further incidents and to bring those responsible to justice.
The U.N. has previously called on the Iraqi government to ensure accountability over allegations of abuse. Several military personnel have been arrested.”
When they asked for water or food or air, they were abused by militia members, told that their treatment was ‘revenge for Camp Speicher,’ and beaten with shovels, sticks, and pipes,” Zeid said, referring to the U.N.-documented killing of 1,700 cadets by Islamic State in June 2014.
Witnesses said at least four men were beheaded, others were handcuffed and beaten to death, and the bodies of at least two men were set on fire, Zeid wrote. People who escape from Islamic State should be treated with sympathy and respect, he said.
“There must be an understanding that most of the male inhabitants of these cities are not willing members of ISIL, nor do they necessarily have anything to do with them at all beyond doing what is necessary to stay alive,” he said.

Volunteers from the Iraqi Ketaeb Hezbollah join the army to fight the Islamic State group, in Baghdad on July 9, 2014.

AFP also reported:

A Shiite militia that fought alongside Iraqi forces against the Islamic State group (IS) may have kidnapped 900 civilians and executed at least 50, some by beheadings and torture, the UN said Tuesday.
The initial phase of Iraq’s vast offensive to retake the city of Fallujah from IS was supported by several Shiite militia, which raised fears of reprisals against the area’s Sunni Muslim population.
UN rights chief Zeid Raad Al Hussein said there was strong evidence that one group, Ketaeb Hezbollah, perpetrated atrocities after telling civilians that they were there to help.
– 900 missing or killed –

Ketaeb Hezbollah fighters approached the village of Saqlawiyah near Fallujah — which lies only 50 kilometres (30 miles) west of Baghdad — on June 1, Zeid’s office said in a statement, citing witness testimony.
Some 8,000 civilians spotted the fighters as they were leaving Saqlawiyah amid the assault on IS.
The militia members “hailed them with loudspeakers, saying the villagers had nothing to fear from them,” according to the rights office.
“Witnesses said that hidden behind the Iraqi flags they saw the flags of a militia called Ketaeb Hezbollah,” the UN statement added.
Women and children were sent to a displaced persons camp while men and teenage boys were taken to a series of locations.
According to witnesses, those who asked for water “were dragged outside and shot, strangled, or severely beaten,” the UN said.
The abducted males were separated on June 5, with 605 men and boys taken to the displaced persons camp.
The whereabouts of a second group, with an estimated 900 people, is “unknown”, according to Zeid.
The rights chief said locals made a list of 643 missing men and boys and “49 others believed to have been summarily executed or tortured to death while in the initial custody of Ketaeb Hezbollah.”
Locals said 200 additional abductees have not been accounted for.
Women in the displaced persons camp at Amriyat al-Fallujah told AFP last month that their sons, husbands and nephews were missing.

Source: Reuters, AFP 5 July 2016