At least 300 refugees died fleeing militants in northern Iraq — and most of the fallen were children, according to doctors at Nawruz camp, where most of the escapees arrived after leaving Mount Sinjar.

Some 150,000 people fled after ISIS militants invaded Sinjar, sending them up the mountain, where they faced the possibility of starving to death.

By now, most have climbed back down, enduring the extreme heat and an arduous trek to safety in Syria or other parts of Iraq. As many as 70,000 people passed through Syria’s Nawruz camp, where they rested and received much-needed aid before continuing the their journey.

“The ones who walked say it took hours,” UN spokeswoman Ariane Rummery said. “They ­arrived covered in blisters.”