Children fleeing the jihadist-held Hawijah area in north Iraq are dying of thirst and being killed by makeshift bombs, Save the Children said on Thursday.
Hawijah, a town in Iraq's Kirkuk province, has been held by the Islamic State group since 2014, and jihadists who have fled defeats in other areas are believed to have gathered there.
"In recent days scores of young children have run out of water and died along perilous mountain paths, or have been killed after stepping on the improvised landmines," the Britain-based Save the Children charity said.
"One family of five, now reduced to three, said they lost two children to hidden explosives. They were unable to retrieve the bodies for fear of further landmines in the area," it said in a statement.
Iraqi forces are preparing for an operation to retake the city of Mosul, the capital of neighbouring Nineveh province, and a push to recapture Hawijah could occur simultaneously.
The Mosul offensive may spark a humanitarian crisis, with the United Nations saying that up to a million people could be displaced by the fighting