Thousands of men and women from Iraq's Yezidi religious group are stranded in northern mountains, according to United Nations groups, as they sought to escape execution and rape by Islamist militants.

About 140,000 people fled from regions in the north this week, including the town of Sinjar where most of the population is Yezidi, according to UNICEF. While most escaped to Kurdish-controlled areas, about 50,000 people, half of them children, "got stranded in the mountains," UNICEF spokeswoman Juliette Touma said. "Their situation is the direst because we cannot provide assistance, provide essential supplies like water."

The attacks on the minority Yezidi group are the latest evidence of the trauma that has gripped Iraq as Islamic State extends its rampage through the country.