( CNN ) ISIS on Wednesday released more than 200 Yazidis , a minority group whose members were killed , captured and displaced when the Islamist terror organization overtook their towns in northern Iraq last summer , officials said . Most of those released were women and children ; the rest were ill or elderly , said Rassol Omar , a commander in the Peshmerga force that defends northern Iraq 's semi-autonomous Kurdish region . Omar did n't say what led to the release , other than asserting that Arab tribal leaders helped to coordinate it . The freed Yazidis were received by Peshmerga , who sent them to the Kurdish regional capital , Irbil , said Nuri Osman , an official with Iraq 's Kurdistan Regional Government . It was n't immediately clear what motivated Wednesday 's release , Osman said . Osman said 217 Yazidis were released . Omar , the Peshmerga commander , had a higher count : 228 . ISIS previously released scores of other Yazidis -- largely children and the elderly -- since attacking the group 's towns last year . The Sunni Islamist militant group steamrolled into Iraq 's north last summer , forcing hundreds of thousands of minorities -- Yazidis among them -- from their homes . Yazidis are of Kurdish descent , and their religion is considered a pre-Islamic sect that draws from Christianity , Judaism and Zoroastrianism . One of the oldest religious communities in the world , the Yazidis have long suffered persecution , with many Muslims referring to them as devil worshipers . ISIS ' cruelty to them has been extraordinary . ISIS ' conquest of the town of Sinjar , in particular , provoked a major humanitarian crisis as some Yazidis fled into the mountains -- where many became trapped for a time without food and water -- and others fled by foot into neighboring Syria . ISIS slaughtered Yazidis by the hundreds , Yian Dakhil , the only lawmaker representing the Yazidis in Iraq 's Parliament , told CNN last year . Reports emerged from some Yazidi survivors that ISIS raped and enslaved female Yazidi captives . An international coalition responded , first by airdropping supplies in the mountains . Rescues came next . And then , starting in August , the United States and other nations conducted airstrikes targeting ISIS in Iraq and Syria . The U.S. State Department estimates that 500,000 Yazidis live in northern Iraq , accounting for less than 1 % of the country 's population . CNN 's Raja Razek reported from Beirut . CNN 's Jason Hanna wrote from Atlanta . CNN 's Hamdi Alkshali , Faith Karimi and Yousuf Basil contributed to this report .
Most of those released were women and children . many Yazidis fled to parts of Iraq 's Kurdish territories .