More than 10,000 Iraqis have fled their homes since the October 17 start of an offensive to retake Mosul from ISIL.
"Over 10,500 people are currently displaced and in need of humanitarian assistance," the UN's Office for the Coordination of Humanitarian Affairs said in a statement.
"Population movements are fluctuating as the front lines move, including people returning to their homes following improved security conditions in the immediate area," it said.
The aid community has been scrambling to build camps and bring equipment to areas on the edges of the Mosul battlefield, a vast area where Iraqi forces are closing in on jihadists from the north, east and south.
