GENEVA >> UNICEF says the children who make up most of the nearly 600,000 Rohingya Muslims who have fled violence in Myanmar are seeing a “hell on earth” in overcrowded, muddy and squalid refugee camps in neighboring Bangladesh.

The U.N. children’s agency has issued a report that documents the plight of children who account for 58 percent of the refugees who have poured into Cox’s Bazar, Bangladesh, over the last eight weeks. Report author Simon Ingram says about one in five children in the area are “acutely malnourished.”

The report comes ahead of a donor conference Monday in Geneva to drum up funding for the Rohingya.

“Many Rohingya refugee children in Bangladesh have witnessed atrocities in Myanmar no child should ever see, and all have suffered tremendous loss,” UNICEF Executive Director Anthony Lake said in a statement.

The refugees need clean water, food, sanitation, shelter and vaccines to help head off a possible outbreak of cholera — a potentially deadly water-borne disease.

Ingram also warned of threats posed by human traffickers and others who might exploit children in the refugee areas.

“These children just feel so abandoned, so completely remote, and without a means of finding support or help. In a sense, it’s no surprise that they must truly see this place as a hell on earth,” Ingram told a news conference in Geneva.

The report features harrowing color drawings by some children being cared for by UNICEF and other aid groups who are scrambling to improve living conditions in Cox’s Bazar. Some of the images show helicopter gunships and green-clad men firing on a village or on people, some of whom are spewing blood.

The influx of Rohingya refugees from Myanmar began on Aug. 25 as the military launched a crackdown it said was in response to militant attacks. Refugees have fled burning villages and provided accounts — like the children’s drawings — of security forces gunning down civilians.

The U.N. and humanitarian agencies seek $434 million for the Rohingya refugees — about one-sixth of which would go to UNICEF efforts to help children.