Iraqis Flee Mosul As Iraqi Forces Attempt To Drive Out ISIS

Thousands of civilians have fled the Mosul area as Iraqi-led forces advance on the city to liberate it from ISIS jihadists. 

The United Nations says civilians have crossed the border into Syria. The BBC reports many of them have fled to a refugee camp where conditions are said to be dirty and overcrowded.

The UN says they expect the retake of Mosul to lead to one of the largest humanitarian crises in modern history -- with millions of people displaced.

U.S. officials told FOX News they expect the Islamic State to use crude chemical weapons, specifically mustard agent since they've used the chemical before in battle.