The operation to retake the northern Iraqi city of Mosul from Daesh has seen a sharp rise in civilian deaths and forced around half a million people to flee their homes, since the start of the US-led campaign six months ago.
Iraqi forces began the country's biggest military operation in years on October 17 last year and recaptured the eastern side of the city in January.
An assault launched the following month on the part of Mosul that lies west of the Tigris river has seen a sharp rise in displacement.
"The sheer volume of civilians still fleeing Mosul city is staggering," the UN's humanitarian coordinator in Iraq, Lise Grande, said in a statement.
Towns have been torn up as Peshmerga and Iraqi forces attempt to drive the terror group out of the city.