"Islamic State of Iraq and the Levant" (ISIL) group fighters reportedly shot dead more than 60 people this week and hung some of their bodies from poles after alleging they had collaborated with Iraqi troops, AFP reported Friday (November 11th).

The UN human rights office has raised alarm over hundreds of grotesque atrocities allegedly committed by ISIL as Iraqi forces have pushed their nearly month-long offensive to retake Mosul , the last jihadist bastion in Iraq.

"On Tuesday, ISIL reportedly shot and killed 40 civilians in Mosul city after accusing them of 'treason and collaboration' with the Iraqi security forces (ISF)," rights office spokeswoman Ravina Shamdasani said in a statement.

"The victims were dressed in orange clothes marked in red with the words: 'traitors and agents of the ISF'. Their bodies were then hung on electrical poles in several areas in Mosul city," she added.

Abu Saif, a resident of eastern Mosul, told AFP by telephone that he had seen bodies strung up in the city along with signs that read "agent" and "traitor".

He did not have an exact count of the total number of bodies, but said he saw between 30 and 40.

"ISIL gathered people in some of the streets of Mosul and publicly executed a number of people of various ages, some of them by gunfire and others by beheading," he said.

According to the UN, a 27-year-old man was reportedly killed in public in central Mosul Tuesday for using a mobile phone, which ISIL has banned in areas it controls.

And on Wednesday, ISIL slaughtered another 20 people at the Ghabat military base in northern Mosul after accusing them of "leaking information", the UN statement said.

"Their bodies were also hung at various intersections in Mosul, with notes stating: 'decision of execution' and 'used cellphones to leak information to the ISF'", the statement added.

All of the killings apparently followed rulings by the so-called "courts" established by ISIL.