"Right now, three thousand Christians are in Iraq fleeing to neighboring cities," he told Mann. Arabo is calling on the international community to follow France's lead and offer the Christians of Iraq asylum.
"You're startling me with the severity of what you're describing," the CNN host said. "You said they are --- beheading children?"
"They are systematically beheading children," Arabo repeated slowly. "And mothers and fathers. The world hasn't seen an evil like this for generations."
"There's actually a park in Mosul where they actually beheaded children and put their heads on a stick... this is crimes against humanity. They are doing the most horrendous, the most heart-breaking crimes that you can think of."
Mann asked about the ISIS letter sent to Christians in Mosul, demanding that they either convert to Islam, pay a fine or be put to "death by the sword."
"It's very clear they are killing people, but are Christians managing to escape by paying a fine?" he asked.
Arabo reports that after Christians pay the fine, the fighters take the Christian wives and children "and make them their wives - so it's really convert, or die."