Irbil , Iraq ( CNN ) -- The offensive by ISIS militants against civilians and religious minorities in the northern Iraqi governorate of Nineveh has created a catastrophe . At least 300,000 Yazidis and 100,000 Christians were displaced literally overnight , according to figures provided by the Kurdistan regional government . Many of the Yazidis fled to the mountains on August 3 after Kurdish fighting forces known as Peshmerga , who were protecting them , precipitously withdrew . For the Christians in villages north of Irbil , the moment came in the wee hours of August 7 , when the Peshmerga silently pulled out . The thousands of Yazidis who had remained stranded on a mountain seem to be getting out for now after U.S. airstrikes helped clear a safe path for escape . But even if they reach a safer place in Iraqi Kurdistan , their longer-term prospects are grim as long as forces of ISIS , which refers to itself as the Islamic State , control the area where they lived . On August 6 , I visited a Yazidi village south of Duhuk -- a magnet for 60,000 to 70,000 of the fleeing Yazidis . They had bread and water but not much else . Many more -- upward of 150,000 -- were on the rugged mountains a dozen or so kilometers north of Sinjar . They found little sustenance or shelter amid the mountains ' sparse vegetation and summer temperatures of up to 120 degrees Fahrenheit . Perhaps 40,000 managed to escape on the northern side that day before ISIS surrounded the mountains . Over the following days , a few thousand more trickled out in small groups , braving ISIS snipers as they made their way north . The latest U.N. field reports say an average of more than 10,000 people a day have been crossing from Syria into the Kurdish region of Iraq by a small bridge at Peshkhabour . Most are Yazidis , who had managed to make it down from the mountains and into Syria , about 20 kilometers ( about 12 miles ) away . Arab neighbors joined ISIS slaughter , escaped Yazidi says . The Yazidis are ethnically related to Kurds but practice a 4,000-year-old religion . ISIS -- indeed many Muslims -- consider them to be `` devil worshippers , '' and the militants seem intent on eliminating them as a religious community and culture . Who are the Yazidis , and why does ISIS want to kill them ? Indeed , Yazidis were the target of what was probably the worst attack against civilians in Iraq since the U.S.-led invasion in 2003 . On August 14 , 2007 , four simultaneous bombings involving a fuel tanker and three cars killed upward of 500 Yazidis , wounded more than 1,500 and destroyed nearly 400 homes . The explosions were so huge that no trace could be found of dozens of people closest to the explosions . There was no Iraqi government investigation . No group claimed responsibility , but it was typical of bombings by the Islamic State of Iraq , predecessor to ISIS , which had reportedly distributed leaflets in the area shortly beforehand denouncing Yazidis as `` infidels . '' The ISIS strategy since capturing Iraq 's second-largest city , Mosul , a month ago is apparently to clear Nineveh -- home to many of Iraq 's religious minorities -- of civilians and anyone who is n't a Sunni Muslim . An ISIS photo spread distributed shortly after the capture of the Yazidi village of Sinjar showed the militants executing people who were clearly civilians . Fast facts on ISIS . At least a dozen Yazidi men told me in the past week that ISIS had abducted scores of women and girls , detaining large numbers in a school in Tal Afar , a town northwest of Mosul . Others were trucked across the Syrian border to a detention center . Asad , a young Yazidi man working in Irbil at the time of the attack , said ISIS abducted 50 members of his extended family as they tried to escape and forced them to drive across the Syrian border . His brother Raad drove one of the cars , his cell phone open on his lap , on speaker , while Asad in Irbil kept adding funds from scratch cards to keep the line open . Raad described over four hours the route that ISIS forced the captured family to drive into Syria . `` I lost contact then , '' Asad said . The next day he tried the numbers of another brother . Someone else answered . `` Do not call , '' that person said . `` We have all their mobiles , we do n't know where they are , '' and hung up .
Joe says : The offensive in northern Iraq a catastrophe for Yazidis and Muslims . Yazidis driven to mountains are now escaping , but the problem remains , Stork says . Others : Some fleeing Yazidis escaped , died in rugged mountains . ISIS considers members of religious minorities to be ` ` devil worshippers , '' he says .